Something I've not mentioned much in the past because it's so hard to prove anything conclusively but Eve markets are thoroughly infested with bots. Cheaters using automated market posting software to constantly, perpetually undercut your sell orders and overcut your buy orders.
It's very difficult for us non-cheaters to prove anything especially since we don't know who's posting which orders unless we play into their hands by buying and selling to their orders just to get a name. Even then in a busy market with multiple orders around the same size it's nearly impossible to keep track of specific orders to figure out which ones are being updated too quickly/frequently and therefore must be bots.
Sometime it's a bit more obvious though. Like very large orders on the main hubs that continually get updated like clockwork all day, week, month, year long. But those are mostly big botters, the experienced "pros" who've been doing it for years. They aren't stupid enough to update too quickly, too frequently or leave any one bot logged in for too long so it's nearly impossible to prove they're bots.
Or even more obvious the obsessive cutter on some backwater station far off the beaten track in one of the less populous regions who's always there cutting your prices within seconds. You can log off for hours, days or even weeks but as soon as you log back in and modify a few prices he'll already be cutting the first ones before you finish the last ones. He'll easily go through 305 orders much faster than humanly possible.
Many of the bots are set so if they cut 3 times in row 5 minutes apart they'll take a break for 3 hours before cutting again. At least one of the Eve bot sellers mentions a feature where it "can tell when someone is screwing with it" and stop cutting for a while (default 3 hours no doubt).
Today I found a very obvious bot working out of Malma I - TransStellar Shipping Storage in Genesis region. I've been wondering for a while why I hardly get any ships from my buy orders on Apanake and Tar, especially since it's mostly just me and one other player buying them... I guess he ran all the rest of the competition off with obsessive, perpetual cuts.
I did have some minor problems with an obsessive cutter on other items in Genesis for a while until he finally realized he wasn't running me off that easy... Especially not on core items I've been working for a long time and know the markets for extremely well. Ships are a bit of a different story, my business in ships is very sporadic, so I didn't realize I was dealing with such an extremely persistent obsessive undercutter in the ship markets.
I finally got around to checking what was going on with my ship buy orders there today. I logged in and updated buy orders for 22 different ships (Mostly T2 and T3) then immediately double checked those same orders. It only took a minute or so to update them all, yet the first ones had already been cut again before I even finished. Long before the 5 minutes when I could modify my orders again was up, every single one of my orders had been cut.
I modified again as soon as possible. Once again the competition had most of them cut by the time I finished. I continued doing this 4 or 5 more times just to see if he'd stop after a few. No such luck, the cycle repeated multiple times over the rest of the day. After the first 5 or 6 times I didn't cut every 5 minutes, I mixed up my timing quite a bit, but I did cut 30 or 40 times in total throughout the day. Every single time, the bot had already cut the first orders before I finished and all of them within a minute or two.
At one point I logged out for 1.5 hours, logged back in, redid the same orders again and got the exact same too quick, too efficient response from the competition again... 3 times in a row 5 minutes apart. It's just not humanly possible to update orders as quickly as he does or to respond as consistently, efficiently and immediately as he does, especially not over long periods of time the way this guy does.
I've no doubt there's a market bot on Malma and he's so obvious about it even CCP should be able to recognize it this time. Hopefully he'll be gone shortly after CCP finally gets around to reading my ticket about it!