Bitcoin behaves like something in between a fiat currency, a stock, and a commodity. So it's clearly investible. I recommend to everyone I know to invest at least 1% of their net worth into bitcoin and other digital currencies.

However, it's super risky, and there's no way that investing your life savings into bitcoin now or at any time in the past was a wise financial decision, UNLESS, you have/had very little money to begin with.

Why is this? Well, I come from a poker background and common poker wisdom and logic suggest that a poker player with a very small bankroll SHOULD risk it all. This is because they can easily replace their bankroll and get back into the action at the same stakes. Conversely, a player with a large bankroll must be way more conservative (and apply the Kelly Criterion or other methods of managing risk), because if they lose a significant percentage of their bankroll it will take them a long time to get it back, and they'll be foregoing earning potential in the meantime.

e.g.

Investor A earns $50,000/yr and has $1,000 in savings to invest. Well, he can just throw it all into any investment he thinks is a good bet. If he loses, all he has to do is work for a week or so and recoup his lost $1,000.

Investor B has a net worth of $10,000,000 and is a professional investor who's been earning 10% on his portfolio for 10yrs. For this guy to bet it all on bitcoin would be ludicrous, because he'd be risking the chance to keep earning $1,000,000 per year, and he'd be needlessly accepting a small chance that he goes completely bust (risk of ruin).