This is my first attempt at a guide to the market, mostly little things I do to pick up all the pennies other players drop, and eventually controlling the market itself.
This requires some patience and a considerable amount of time. The goal is to pick up a few hundred gold here and there, and hoping that eventually they add up.
Here are the categories of things you can purchase with gold, and I will go over each one
Please note that each game's dynamic is different, so the numbers here are served as examples, and you really have to get a feel for your particular game to determine what you want to do, with regards to pricing.
If you were to learn one thing, remember: ALWAYS DO THE MATH
Getting a feel for the market
It is super important that you know what kind of game you're in. This might mean going into most of the active players' cities to see what they are producing, and anticipate needs. If you go farm when there's too much food in the world, you are not operating at a max efficiency.
After that, prepare to spend some time monitoring the markets. See where the numbers go, and where it likes to stabilize. Have an internal number you're comfortable with.
And don't go into the casino with money you cannot afford to lose -- if you can't afford to lose, don't put money on it. In the early game, the market can stay irrational longer than you can be rational!
Market mechanics
The market system is based on last buy/sell price. So the simple logic is this:
Whenever you buy an item, its buy/sell price will go up.
Whenever you sell an item, its buy/sell price will go down.
It does not try to find a counterparty for your deal -- meaning effectively you can manipulate the market if you can afford to do so. You are selling to the bank.
There is a spread to each item -- the difference between the buy price and the sell price. For the top-row items (resources and commodities) the spread is small, and basically if you buy and then sell back to back, you'll effectively break even (sometimes you lose $1, maybe due to rounding).
Now try buying the same item multiple times in succession, its price will go up a few increments. Now try to sell the same item multiple times. Its price will go down.
So this is the takeaway about the market mechanic:
If you want the price of something to go up, buy it until it's at a price you want it to be!
If you want the price of something to go down, sell it until it's at a price you want it to be!
Here's a short example of how to make money:
Buy price of food = 440. You believe it should be more in the 500 range.
Buying it 4 times:
440->463->487->513
Now the buy price is at 598.
It costs you:
440 + 463 + 487 = 1395
Now player A needs 300 foods:
A buys it 3 times:
513->540->568->598
513 + 540 + 568 = 1621
Now food is at nearly 600! You can sell it back down to 500:
(Sell prices is one step down from buy prices)
568->540->513->487
So you sell it 3 times for:
568 + 540 + 513 = 1621
which is how much player A paid. You just net a cool 220 gold!
Harvest/trickle resources:
Now punctuator has a <a href="http://forums.civfanatics.com/showthread.php?t=430544">guide</a> which explains these resources. This guide will try to go into how these things affect the market in particular.
Food. This is useful in one thing only, for growth. How much does your world value growth? An advance scouting will allow you to know who is "close" in popping. Then, when that player comes on, what will he notice? That he will need only X amount of food to pop. The average player will not mind that he is paying an extra few hundred per 100 foods. After all, he is so close! In fact, maybe it's even worth it for him even with the extra cost, depends on the math.
Wars and buildings. Early game there will be plenty of demand as everybody need to build those houses and structure and exploration. If someone's city just grew, they might need to build new houses and structures. At some point there will be more wars. Gauge how blood thirsty your world is! You can scout civs' intent to invade by looking at their civ screen -- they have to vote to go to war! One-sided wars will not do much for business, but given two motivated side with plenty of wonders to lose, everyone will try to one up each other. Prepare for this way in advance by buying hammers when they're cheap, raise the price when the war is starting, and sell when it's high enough.
Science. For science. The hardest part about trading science is if you're not careful, you might actually research something by accident, and everything goes down the pipe! Science actually goes away if you complete something, and all the extra ones are lost. The obvious move here is do the math first to see what you need, and if you have any extra, sell them, even at prices you would consider too low. As soon as the tech unlocks, you can buy the tech back up to where you expect them to be. This one is a little tricky to scout, as players also hide their beakers in other techs so it's not super reliable. If you can somehow anticipate someone's close, you can buy it up and selling it after another civ pops it. You can also easily scout your own civ, but that might be kill a little teamwork. 
Culture. This one might be the most unpredictable and hard to scout of the bunch. This is usually relatively cheap, so you can treat it as a commodity for trading, except for properties of a commodity that we'll discuss later. Of course, just remember if you're buying a bunch cheap, don't go over for the Great Person unless you want to! You'll lose all your puzzle moves!
General notes, things to mind:
[*] People tend to buy things in bunches. Given how the market works, this means the buyers buying in bundles will actually pay more then the ticket price! (Some people might do the math as the ticket price times the number they want, but this is incorrect in a bundle.)
[*] Early game especially, but also true for cash-strapped nations (perhaps salvaged by wars, or dubious financial decisions -- you can scout this on the civ screen, and look at everybody's wealth) in order for them to buy something, they need to sell something. They will typically do both in bunches as per the previous point. Take both side of the trade!
Commodities
I believe these commodities just take some random fluctuations. It is affected somewhat by world supply/demand, but as nobody really needs commodities, I'm guessing the randomness is there to keep things from being too stall -- otherwise there's really no reason to buy these as then it'll be a pure zero-sum thing with not much upside or usage.
In any case, commodity pricing follows the same spread as the resources. Your average price is displayed in the corner, allow you to remind yourself to always make a profit, assuming you're okay with the timeline.
They are also a great way to make money, but the disclaimer again: Only play with money you don't need! If you're forced or tempted to sell your things (at a loss) for food, don't buy commodities!
My model for the commodities is as such:
I think of the expected value of a commodity rises slowly through time, but with some (sometimes large) fluctuations throughout. There's only one end point -- the end of the game. Otherwise, you can always take a profit (even if it takes awhile). Because the fluctuations could be quite large, even within the same real day, it is actually less risky, because you know it will hit some high point sometime in the day. You just have to be online to reap the benefits.
I'll have to add a drawing at some point, but the obvious is this: buy low, sell high. Monitor the commodities, and see what point it rolls around.
My strategy is, I set a bottom price that I think it won't drop lower than, and keep on buying it until it gets to the price I like. If it drops, I double down by buying even more -- as long as I'm comfortable with it! When it gets to a nice profit point, I will sell them. You can bunch a few, but if you have a large stock, you should wait it out a little bit longer, to avoid crashing the price too much.
I've seen a commodity trading from 200 to 900 back to 400 on the same day, so it's definitely not for the faint of heart, but it's a really good way of making a profit if you have cash, and can stomach it.
Military
Military units are built using hammers, so hammer part about anticipating wars and demands as cities grow applies here. For the purpose of the market I only consider two things -- a unit's sell price, and its hammer cost.
The math should be simple. You can calculate a unit's "gold price" for you as such:
Take the unit's hammer cost. Let's say Artillery at 200 hammers. The cost of 100 hammer is at 323. So the effective price of an artillery would be 323 + 340 = 663.
Now check the market for the artillery's sell price. Is it higher than 663? If not, move on to the next unit.
If so, there are now two types of related trades you can do. You can buy the 200 hammers for 663, build the artillery, and sell the artillery at the sell price. The hammer price will now be up, and the artillery price will drop a little bit. Do the math again, and repeat until this is no longer the case. Congrats, you just received free money!
The other scenario is if you have a lot of hammers and wants to just sell them, but the market isn't quite as high as you want it to be. Build the artillery and then simply sell it. Basically you just sold 200 hammers for whatever the sell price is!
The spread for units is high, which makes it difficult to do a quick turnaround sale. The selling price is 60% of the buying price -- so you lose 40% off the buy immediately. If you anticipate war and see a unit's cost as fairly cheap, and should be relatively popular (the "base" units), then by all means stock up. For whatever reason, players are relatively irrational -- they will pay for a unit on the market for more than its effective cost by buying hammers. If your game is full of rational people, this might not be a good gambit.
*I'm using the neutral he as the pronoun, please forgive me.
This requires some patience and a considerable amount of time. The goal is to pick up a few hundred gold here and there, and hoping that eventually they add up.
Here are the categories of things you can purchase with gold, and I will go over each one
- Food/Production/Science/Culture
- Military
- Great Persons
- Commodities
Please note that each game's dynamic is different, so the numbers here are served as examples, and you really have to get a feel for your particular game to determine what you want to do, with regards to pricing.
If you were to learn one thing, remember: ALWAYS DO THE MATH
Getting a feel for the market
It is super important that you know what kind of game you're in. This might mean going into most of the active players' cities to see what they are producing, and anticipate needs. If you go farm when there's too much food in the world, you are not operating at a max efficiency.
After that, prepare to spend some time monitoring the markets. See where the numbers go, and where it likes to stabilize. Have an internal number you're comfortable with.
And don't go into the casino with money you cannot afford to lose -- if you can't afford to lose, don't put money on it. In the early game, the market can stay irrational longer than you can be rational!
Market mechanics
The market system is based on last buy/sell price. So the simple logic is this:
Whenever you buy an item, its buy/sell price will go up.
Whenever you sell an item, its buy/sell price will go down.
It does not try to find a counterparty for your deal -- meaning effectively you can manipulate the market if you can afford to do so. You are selling to the bank.
There is a spread to each item -- the difference between the buy price and the sell price. For the top-row items (resources and commodities) the spread is small, and basically if you buy and then sell back to back, you'll effectively break even (sometimes you lose $1, maybe due to rounding).
Now try buying the same item multiple times in succession, its price will go up a few increments. Now try to sell the same item multiple times. Its price will go down.
So this is the takeaway about the market mechanic:
If you want the price of something to go up, buy it until it's at a price you want it to be!
If you want the price of something to go down, sell it until it's at a price you want it to be!
Here's a short example of how to make money:
Buy price of food = 440. You believe it should be more in the 500 range.
Buying it 4 times:
440->463->487->513
Now the buy price is at 598.
It costs you:
440 + 463 + 487 = 1395
Now player A needs 300 foods:
A buys it 3 times:
513->540->568->598
513 + 540 + 568 = 1621
Now food is at nearly 600! You can sell it back down to 500:
(Sell prices is one step down from buy prices)
568->540->513->487
So you sell it 3 times for:
568 + 540 + 513 = 1621
which is how much player A paid. You just net a cool 220 gold!
Harvest/trickle resources:
- Food: Growth and people
- Hammer: Buildings and Military
- Science: Research techs
- Culture: Creating Great Person
Gold: Currency
Now punctuator has a <a href="http://forums.civfanatics.com/showthread.php?t=430544">guide</a> which explains these resources. This guide will try to go into how these things affect the market in particular.
Food. This is useful in one thing only, for growth. How much does your world value growth? An advance scouting will allow you to know who is "close" in popping. Then, when that player comes on, what will he notice? That he will need only X amount of food to pop. The average player will not mind that he is paying an extra few hundred per 100 foods. After all, he is so close! In fact, maybe it's even worth it for him even with the extra cost, depends on the math. Wars and buildings. Early game there will be plenty of demand as everybody need to build those houses and structure and exploration. If someone's city just grew, they might need to build new houses and structures. At some point there will be more wars. Gauge how blood thirsty your world is! You can scout civs' intent to invade by looking at their civ screen -- they have to vote to go to war! One-sided wars will not do much for business, but given two motivated side with plenty of wonders to lose, everyone will try to one up each other. Prepare for this way in advance by buying hammers when they're cheap, raise the price when the war is starting, and sell when it's high enough. Science. For science. The hardest part about trading science is if you're not careful, you might actually research something by accident, and everything goes down the pipe! Science actually goes away if you complete something, and all the extra ones are lost. The obvious move here is do the math first to see what you need, and if you have any extra, sell them, even at prices you would consider too low. As soon as the tech unlocks, you can buy the tech back up to where you expect them to be. This one is a little tricky to scout, as players also hide their beakers in other techs so it's not super reliable. If you can somehow anticipate someone's close, you can buy it up and selling it after another civ pops it. You can also easily scout your own civ, but that might be kill a little teamwork. Culture. This one might be the most unpredictable and hard to scout of the bunch. This is usually relatively cheap, so you can treat it as a commodity for trading, except for properties of a commodity that we'll discuss later. Of course, just remember if you're buying a bunch cheap, don't go over for the Great Person unless you want to! You'll lose all your puzzle moves!General notes, things to mind:
[*] People tend to buy things in bunches. Given how the market works, this means the buyers buying in bundles will actually pay more then the ticket price! (Some people might do the math as the ticket price times the number they want, but this is incorrect in a bundle.)
[*] Early game especially, but also true for cash-strapped nations (perhaps salvaged by wars, or dubious financial decisions -- you can scout this on the civ screen, and look at everybody's wealth) in order for them to buy something, they need to sell something. They will typically do both in bunches as per the previous point. Take both side of the trade!
Commodities
I believe these commodities just take some random fluctuations. It is affected somewhat by world supply/demand, but as nobody really needs commodities, I'm guessing the randomness is there to keep things from being too stall -- otherwise there's really no reason to buy these as then it'll be a pure zero-sum thing with not much upside or usage.
In any case, commodity pricing follows the same spread as the resources. Your average price is displayed in the corner, allow you to remind yourself to always make a profit, assuming you're okay with the timeline.
They are also a great way to make money, but the disclaimer again: Only play with money you don't need! If you're forced or tempted to sell your things (at a loss) for food, don't buy commodities!
My model for the commodities is as such:
I think of the expected value of a commodity rises slowly through time, but with some (sometimes large) fluctuations throughout. There's only one end point -- the end of the game. Otherwise, you can always take a profit (even if it takes awhile). Because the fluctuations could be quite large, even within the same real day, it is actually less risky, because you know it will hit some high point sometime in the day. You just have to be online to reap the benefits.
I'll have to add a drawing at some point, but the obvious is this: buy low, sell high. Monitor the commodities, and see what point it rolls around.
My strategy is, I set a bottom price that I think it won't drop lower than, and keep on buying it until it gets to the price I like. If it drops, I double down by buying even more -- as long as I'm comfortable with it! When it gets to a nice profit point, I will sell them. You can bunch a few, but if you have a large stock, you should wait it out a little bit longer, to avoid crashing the price too much.
I've seen a commodity trading from 200 to 900 back to 400 on the same day, so it's definitely not for the faint of heart, but it's a really good way of making a profit if you have cash, and can stomach it.
Military
Military units are built using hammers, so hammer part about anticipating wars and demands as cities grow applies here. For the purpose of the market I only consider two things -- a unit's sell price, and its hammer cost.
The math should be simple. You can calculate a unit's "gold price" for you as such:
Take the unit's hammer cost. Let's say Artillery at 200 hammers. The cost of 100 hammer is at 323. So the effective price of an artillery would be 323 + 340 = 663.
Now check the market for the artillery's sell price. Is it higher than 663? If not, move on to the next unit.
If so, there are now two types of related trades you can do. You can buy the 200 hammers for 663, build the artillery, and sell the artillery at the sell price. The hammer price will now be up, and the artillery price will drop a little bit. Do the math again, and repeat until this is no longer the case. Congrats, you just received free money!
The other scenario is if you have a lot of hammers and wants to just sell them, but the market isn't quite as high as you want it to be. Build the artillery and then simply sell it. Basically you just sold 200 hammers for whatever the sell price is!
The spread for units is high, which makes it difficult to do a quick turnaround sale. The selling price is 60% of the buying price -- so you lose 40% off the buy immediately. If you anticipate war and see a unit's cost as fairly cheap, and should be relatively popular (the "base" units), then by all means stock up. For whatever reason, players are relatively irrational -- they will pay for a unit on the market for more than its effective cost by buying hammers. If your game is full of rational people, this might not be a good gambit.
*I'm using the neutral he as the pronoun, please forgive me.
