2500sat is a huge resistance zone, many will try to get out at breakeven. Buyers are hoping for despair to set in for cheaper prices.
Selling under ICO price does not necessarily mean you won't profit. The trick is to make more SNGLS before its first rally/bubble. Sell 100 SNGLS at 2500 and buy back 166 SNGLS at 1500 and then when you're done you can exit forever at 10,000 sats above (when it happens). You don't necessarily have to sell at a loss and move on to other coins, this is still a promising project.
You can't understand why it dropped so hard? That's altcoin markets for you. See https://medium.com/@drei4u/folly-of-altcoin-buy-and-hold-strategy-d7d702ff05d5#.fm56ctuiw
I will also supply some examples to say choosing and holding right coin important.
1, NXT, if you were the 1st lot invester, you will get 1000~10000 times reward
2, Amp, if you invested in the 1st lot ICO, you will get 30~50 times reward.
3, Augur Rep, if you invest in the 1st lot ICO, you will get 20~40times reward.
4, Eth, another good invest example.
choosing and holding the right coin, its profit is bigger a trader frequency trading profit.