What days should you buy or sell on the Auction House?

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There's no question that time is a very powerful influencer of prices. Most typically, time affects prices via inflation, the natural and inevitable tendency of things today to cost more than things cost yesterday. But that's far from the only way that time affects prices. A Love Is In the Air holiday pet is likely going to be less expensive to buy now than if you wait nine months from now. The cost of i397 BoE gear is going to continue to decay right up to the launch of the next expansion.

It's not a phenomenon unique to the game, of course. Those Super Bowl cakes are going to be a lot cheaper at the supermarket today than they were on Saturday. And if you can wait until January to shop for your winter clothes, you're going to get a far better deal than if you do it in October. A lot of prices are cyclical.

But how do those cycles work in the game? If you're a buyer of mats, when should you head to the Auction House to grab what you need? If you're a seller of ore, should just skip listing it certain days to maximize your profits? Let's see what the data say.

The four rules of timing

Rule #1: There's no perfect pattern. Existing data allows us to make a number of generalizations about market behavior, and we'll talk about them in a few moments. First, however, it's very important to note that there's no perfect pattern. That stack of Whiptail could be expensive one Tuesday and cheap the next; there could be excessive quantities one Friday and virtually no stock available the week after. Still, looking at the data, we can see some general patterns.

Rule #2: Tuesdays are special. Tuesdays are easily the most volatile of all the days to either buy or sell. This may not be a surprise for most people, because servers typically reset on Tuesdays. That means more people are playing, more people are raiding (and thus buying mats), and in many cases, that means intrepid auctioneers are putting in the extra effort to meet the demand.

If any one of those factors is more pronounced than the other -- say, a new patch leads more people to buy materials for raiding -- then demand gobbles up all the supply, and the market price spikes. If demand is weaker, then excess supply builds, forcing prices lower.

How does this work in-game? Take a look at this graph of Volcanic Potions on the economically mature Proudmoore server:

Take a look at the red arrows. The red dots represent quantities on Tuesdays, as the servers are coming back online after maintenance or reset. The red arrow represents the change in quantity available from Tuesday to Thursday. As you can see, the general pattern here is for supply to be at its highest right as servers reset, followed by a sharp decline over the next few days. Once supply peters out, it begins to rebuild over the next few days until demand reappears on Tuesday. On weeks where suppliers simply don't post auctions, as is the case of the final arrow, there really isn't any room for supply to dip.

Prices, represented by the blue fill, are a bit less predictable. There are a few occasions, like the second arrow, where prices jump sharply from lack of supply. (These exorbitantly priced auctions likely struggled to sell.) For that week's stretch where supply was miserably low (the fourth arrow), the market behaved as you'd expect -- the price for Volcanic Potions jumped nearly 50% for the duration of the low supply.

What would my recommendation be for this particular market based on the graph? Well, the sharp movements of price suggest that this is an underserved market. There may be some major players supplying the AH, but they're not consistent, and there are frequently periods when supply drops down near 0. This server's Volcanic Potion market is absolutely ripe for someone to come in, monopolize supply, and take the lion's share of the sales at a price just below the current equilibrium.

Rule #3: Weekends are for manufacturing. If supply normally declines following the Tuesday reset, when does the market work the hardest to restock its supply? The weekends. Take a look at this graph, representing Inferno Rubies:

Taking a look at the blue fill, we can see that prices are actually somewhat stable. That means the market is actually functioning pretty well. If you're making Inferno Rubies, you can be pretty sure that the value of your stack will be the same regardless of whether you sell it today or tomorrow, this week or next week, and possibly even this month or next month.

I've circled weekends in green, where you can see the quantities spiking. This is actually true for a large number of different markets; more players are active on weekends, and thus, more auctions get listed. The spikes don't have an appreciable affect on price, in this case. According to this graph, Inferno Rubies have been holding in the same 210 to 230 range almost all year long. That's because the Inferno Ruby market on the shown server is stable.

If you're a regular shopper for rubies, herbs, or ore, and the Auction House is typically well stocked, when you buy your mats isn't especially important, since prices are relatively stable. That said, there are a few instance on the graph where quantity dips low and the price does spike for a bit. That's a good lesson. If you regularly trade in rubies, it's worth keeping a small reserve on hand to avoid those short-lived but inevitable spikes.

This might be a good time to note that, for many raw materials, the quantity supplied on the AH has been in decline since after Christmas 2011. When there is a permanent decline in desire to farm, there will be a similarly permanent increase in prices of the farmed mats. This is why you may be noticing that Whiptail is more expensive now than it used to be for most of the expansion, for example.

Rule #4: Do your business when no ne else is around. As we head into the late-expansion doldrums, fewer people are participating in the market. That means you have fewer competitors. That's definitely good news, but to be truly successful, you need to know what those competitors are up to.

Think of it this way: You want to be the Walmart of your server -- someone who absolutely dominates and controls the market through volume and profit. But to have that kind of success, you need to know what Target and Kmart are doing. Are they putting their stock online every day at 9 p.m.? Add them to your friends list, and then list your auctions once they go offline for the night.

This kind of strategy isn't absolutely necessary, especially if you're all participating in a high-volume market like raw materials (Inferno Rubies, above). For smaller markets where undercutting gets auctions sold (like the Glyphs market, for instance), watching the clock pays off big.

Maximize your profits with advice from Gold Capped. Want to know the very best ways to earn 10,000 gold? Top gold making strategies for auctioneers? How about how to reach 1 million gold -- or how one player got there and then gave it all away? Fox and Basil are taking your questions at and