Games and tools
Every game and calculator on the blog, in one place.
Position size and risk of ruin
Start with $10,000 and make 100 trades at fixed odds. You choose one thing: how much of the account each trade risks. The page counts how often that choice ends ahead, and how often the account falls to $5,000 first.
Guess the gap
A company reports earnings. You see the move options had priced. Guess how far the stock moved the next day.
Implied move from a straddle
A straddle's price tells you how big a move the options market is pricing. Type the two numbers and see the range.
The 60% coin
A coin lands heads 60% of the time. You start with $25 in play money and bet on heads every flip. You pick only how much to bet.
The overnight call calculator
You hold a call overnight. The stock moves and implied volatility changes. See what the call is worth the next morning and where the change came from.
The option payoff calculator
Pick an option structure. See what it is worth on its last day at every stock price, and where it breaks even. Then change its strikes and premiums.