Staying in the game

The lesson in full

Win half your trades and you're doing fine. But over 100 trades, there's about an 80% chance of at least 5 losses in a row. Bad runs are normal.
Risk of ruin is the chance that a losing run shrinks your account so much that you can't recover, or can't keep trading at all.
Ten losses in a row, risking 1% of your account each time: you're down about 9.6%. Risking 10% each time: down about 65%.
Losses dig a hole deeper than it looks. Down 50%? You need +100% to get back. Down 65%? You need about +187%.
Common mistake
Myth: "My strategy wins, so I can risk big." Reality: a winning strategy can still go broke. One bad run at high risk can end the game before your edge shows.
Key takeaway
Keep risk per trade small, often 1 to 2%. Surviving the bad runs gives your edge the time it needs to work.

A 50% loss needs what gain to get back to even? 100%Half your money is left. To get back to the start, that half has to double: +100%.
Ten losses in a row at 10% risk per trade leave you down about... 65%Each loss takes 10% of what's left, not of the start. After ten losses, about 35% of the account remains.
Why do professionals keep risk per trade small? To survive losing runsSmall risk keeps a bad run survivable, so the account is still there when the edge shows up.
You win half your trades. Over 100 trades, 5 losses in a row is... Quite likelyWith a 50% win rate, the chance of at least one run of 5 losses in 100 trades is about 80%.