How to judge their stability/ liquidity ? It is just that bit easier to operate an exchange without withdraws, especially if you can't cover all withdraws. That is my scare. But if I can double the investment quickly ... might be worth. I just do not want to burn again like with Mtgox.
Poloniex and Bitfinex both have withdraw delays or not processing all together.
On Bitfinex is from few months. No one is panicking and hepefully no reason to. I am just researching using these exchanges ... and want to know more about them. Why people are not bothered by this situation ?
https://www.bitfinex.com/posts/201 Probably because Bitcoin withdrawals work properly? At the end of the day they are able to move their money out of the exchange if the want to, they just need to use other exchange to convert it to dollars.