They even didn't make any announcement for clients about the necessity to place orders once again. The orders just disappeared. Decent exchanges shouldn't do such things, do you agree?
I'm sorry this happened to you, but I don't feel it's Bittrex's fault. They do state in their terms that orders are removed after 28 days, which is different from other exchanges. I know in this world nobody has time to read the fine print anymore, but it is your responsibility if you're trading to find out this info. Just take it as a lesson.
Thank you for this info, I didn't knew it also. But in this particular case, I think the truth is that Bittrex opened completely new market XMY-BTC as was written above, with blank orderbook. I suppose that because my order history in XMY-BTC is blank, but I actually had a lot of completed orders on MYR. So, it doesn't matter, was it old MYR order (>28 days) or new one (<28 days) - it just left in closed MYR-BTC market and was not executed. This is, for sure, the fault of Bittrex.
