I have played several times in secondstrade in past and I have never got any problem while betting with them. They allow you to bet on forex markets and they don't have high minimum limits, but I am quite concerned about their source of data. They haven't made that public and on small time frame bet we can't find proof that the numbers they displays are correct or fair.
However it looks like they are currently down and will come up with litecoin, this might be because of high fee we have right now on every bitcoin transactions.
We have an opposite experience on Secondstrade, When I first play on that site, My bet didn't appear on their site until my assumed bet won and still don't have profit received, I contact support but they said that they din't received my bet even though I provide my TXID of my deposit. After that, I never used that site again, I didn't file a complain because it is just a small amount.