I do pretty much the same but I look for historical fluctuations and predict them, if something is soaring way beyond its general pricerange with no underlying reason i will keep away.
If those snaps had not gone up but down from their artificial high instead how many millions would you have lost?

I sometimes fail, but 90% success rate is not to be sneezed at, even if I do end up waiting around a week or two for things to sell again lol
(By the way, 2 weeks ago I made 18.4M on black chaps alone when I bought for 5300 and sold for 6100 a day or two later lol)