The difference between risk and ruin

This is the single most important idea in the track. Risk is losing some money. Ruin is losing so much that you can no longer recover — the account is gone, or so small that no realistic return brings it back. They are different in kind, not just degree.

Why losses are not symmetric

A loss and a gain of the same percentage do not cancel. If you lose 50%, you need a 100% gain just to get back to even. The deeper the hole, the steeper the climb out:

Lose 10%  ->  need +11.1% to recover
Lose 25%  ->  need +33.3% to recover
Lose 50%  ->  need +100% to recover
Lose 75%  ->  need +300% to recover
Lose 90%  ->  need +900% to recover

Small drawdowns are survivable arithmetic. Large ones are nearly fatal — the recovery they demand is unrealistic. This curve is why capping the downside matters more than chasing the upside.

The risk of ruin

Even with a winning strategy, risking too much per trade can wipe you out before the edge pays off. A run of losers is not just possible, it is guaranteed eventually — flip a fair coin long enough and you will see ten tails in a row. If each loss costs 20% of the account, that streak is the end. If each costs 1%, it is a bad week.

The survival mindset

Professionals obsess over the downside, not the upside, precisely because of this asymmetry. Their first question on any trade is never "how much can I make?" but "what happens if I am wrong, and can I survive it comfortably?" Get the second question right consistently and the first takes care of itself over time. The rest of this track is the toolkit for answering it.