Bitcoin is in, it is celebrated, it is rehabilitated... The Times, the President and so on. Everybody says that it is not scam, everybody assures that it is a good thing.
All this means that the risk level on Bitcoin as well as altcoins is lower than ever before. And the prices of altcoins are moderate, in fact they have not increased remarkably relative to previous years.... Does it mean that it is right time to buy or that this right time is near ? (I do not suggest to buy BTC with 100 000 USD !)
The only important thing is the risk/reward ratio.
Overall the holding time should always be long term if you are looking to succeed no matter what happens in the short term. If you are pondering whether to buy on a short term time frame, you will always be waiting for it to go cheaper, or will always be stressed with general volatility. My suggestion is to not worry too much about the price and think more about what you can afford to hold over a long time frame (4 years plus) as this has not failed anyone since bitcoin began. As for altcoins, they're a different game. Unless you are a good researcher and trader who is able to stay on top of changes within a project and read between the lines/filter out the noise, it's a high risk high reward game as you said. I wouldn't call Bitcoin the same game if Bitcoin continues to remain secure in the long run.