Wikipedia:

An investor is a person that allocates capital with the expectation of a future financial return.
A trader is person or entity, in finance, who buys and sells financial instruments such as...

So if you use exchanges to trade - you are not an investor, you are trader. If you hold coins for future returns - you are investor.
And both make money.

As for Stocks Exchange, yesterday I posted Heads Up warning to all here that STEX exposes abnormal behaviour. Posted screenshots and suggested to take coins back. At that time I got withdrawals literally in 2 minutes. I regret that you have issues getting coins back, I was afraid to have the same, so warned ASAP so people could do the same. I hope they will recover funds. But as for me, I will never use this exchange due to its complete lack of support (again, see what I've written yesterday).