Fair point - sort off. I agree that value investing of the...

Fair point - sort off. I agree that value investing of the purest (perhaps) form is one where the risk-reward equation is inverted (the less you pay, the higher the return and the lower the risk). So inverted when compared to the conventional wisdom (dogma) of risk versus reward.

However, mathematically, I would suggest rational investing is about an adequate expected return (ie probability weighted return) with a manageable level of risk. A manageable level of risk need not be zero risk. It can be one which is substantial, but where there will be sufficient similar opportunities (in ones lifetime, or other desired timeframe) such that bet sizing will prevent wipe-out and allow one to reach the expected return in that timeframe. Of course, the expected return needs to be attractive enough.

The advantage of the "purer form" of value investing, is that one need not estimate the downside odds (the risk) or the expected return, with mathematical precision. In fact, rough and ready (though realistic) estimates will suffice. After all, investing, unlike betting on cards or dice, does not come with calculable odds (generally), and usually is not (though often it is) about binary outcomes.

But let me ask you this, what is the probability weighted outcome of catching a flight? When the downside is death, what is the probability weighted downside? It's not like a complete financial loss (-100% return) which is finite. It's kind of like an infinite loss. An infinite negative number multiplied by a small probability, is still an infinite negative number.