Of course it's in a bubble, it's naive to think that we won't have a massive crash because "this time is different - we have institutional investors". But this doesn't mean that it's bad to invest in it, you can try to do some short-term trading and exit long before the crash, you can try to buy dips and sell them quickly, and dips will happen because there's always corrections in the bull market. Bitcoin is a risky investment, but the risk is justified, so the only thing investors should worry about it so not overexpose themself to it.