Losing in trading on purpose might be possible. Let your ratio be cash:loan=10:90 or more.
If you repeat many times, you soon will be broke, even if you win some times.
Best way to lose fast is such as 1:99. Most likely less than ten bets shall make you empty pocket.
If you bet is 100:0 (purely cash), then losing on purpose is as much as difficult as winning, if there is no commission and tax.
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Furthermore, one significant difference is that someone give you loan with collateral in equity, while no one give you loan in poker chip.
Your talking about using leverage. Leverage is just a tool you can use if you have an edge.
Just imagine there is no leverage. Your trading purely the equity you have in your account.
(eg you have $100,000 USD in your account, and you only take positions of 100,000 or less, so that you dont need to borrow anything from your broker)
From there, can you lose on purpose?
As for using leverage to lose quickly, does that mean the opposite is true. Using no leverage (or negative leverage whatever that might be) would give you a positive edge.