This is supposed to illustrate that on short time horizons and with a limited bankroll, risky assets (such as stocks) might cause you to lose your bankroll before less risky assets.
No arguments there. I was extending the time horizon to illustrate a nuanced point.
With roulette, time (the number of times you spin) is against you. The shorter the better.
With equities, time (literally, time in the market) is on your side. The longer the better.
In that regard, with roulette, color bets versus number bets have
very different risk profiles if you have a very short time horizon; say 5 spins of the wheel. Color bets could be likened to bond investments where you stand something close to a 50/50 chance of breaking even over the very short term. With a single number bet (I'm using it as a proxy for equities), you have an extremely low chance of leaving the casino with any chips at all after only 5 spins. The two bets are only comparable (meaning equally likely outcomes) over a series of games played in 37 game increments.
With only 5 spins of the wheel, the number bet is bucking pretty severe odds of walking out of the casino with any money left at all. If you beat those odds, on the other hand, you of course could walk out with substantially more money than you came in with.
So mathematically, the odds of the two bets are about the same; which you can't really say about stocks vs bonds. But the volatility of the two bets are at opposite ends of the spectrum; which I think goes more to your point, i.e., the shorter your time horizon, the less tolerance for volatility you can bear. This is true both in roulette and in financial markets. This makes the single number bet
much more risky, in terms of realizing a total loss, than the color bet, in the very short term.
In financial markets you can mitigate the volatility by extending the time horizon if you are properly diversified. In roulette, extending the time horizon mitigates volatility too, but then you suffer a locked-in negative rate of return that becomes increasingly more probable as time goes by, by doing so, regardless of which bet you select. Because of differences in volatility, the two bets are only equivalently bad, i.e., "risky," over the long term, but not over the short term.
If you only get 5 spins and you are risk-averse, you bet the colors. If you want to go for broke and swing for the fences, you bet the numbers. You could win or lose everything either way, but the odds of losing everything are very different in a series of games lasting fewer than 37 spins of the wheel.
If you want to enjoy your free drinks and kill a bunch of time, you can mix and match your roulette bets however you please. The longer you play, the less your choice of bets will matter, and the less likely you are to realize that those drinks weren't really free after all; not until after you sober up, that is.
Edit to add: And yes, I stand corrected. The best way to mitigate risk in roulette is to go see a movie, instead of playing roulette. ;)