Yesterday, I noticed the price to buy 100 CE was around 7,200, while the price to sell was over 7,400. I realized that this meant I could buy energy and sell it right away for a ~50 Crown profit per 100 CE. I thought the 2% seller's fee was there to prevent this sort of thing and encourage longer-term investments, but I ended up making 800 crowns in five minutes or so. I could have made more, but I worked in small increments to minimize loss.
I usually only buy CE for crafting, and I've never sold it before, so I really don't keep an eye on the market. I was wondering if this is usually the case, or if I found a lucky fluke. Right now, the gap between the prices is small enough that you would lose money if you tried this.
Gap between CE buy/sell prices, free money?
This is called arbitrage, and OOO has never expressed problems with people doing it in either Spiral Knights or in OOO's Puzzle Pirate's game which has had an almost identical market for many years. The 2% fee on selling requires the price spread between the buy offers and sell offers to be at least that large before arbitrage can happen.
Players making arbitrage trades are good for the game. It is important to realize that the list of buy orders for CE on the energy market screen is not really related to the list of CE sell orders. The buy orders are not filled by the sell orders, but rather the CE buy orders are filled by people using the quick "buy crowns" button on the energy trade screen. If there are, over the long run, more people pressing the "buy crowns" button than there orders placed via CE buy orders, then the list of buy orders would eventually run dry and the market would stop working. By players making arbitrage trades, they are doing the work of balancing out the number of 100CE blocks between these two screens. They are puttng their crowns/CE at risk to a changing market and spending time, and so there isn't anything wrong with them making a profit.
The more people who do arbitrage trades, the slimmer the spread will be and therefore the lower the profits.
now that the market has slowed down i dont see it happening as often, but this used to happen in mass amounts quite a bit and you could make easy 75-100cr profit per transaction when it was around 6k.
i havent observed it for a few weeks but i think its always like this 24/7
you were lucky, it happens once in a while..