I'm surprised that the posters here want that sort of performance.

Here's something that might be a better approach:

"HOW TO PLAY A DOUBLE"

Regardless of the asset class (this approach also works for stocks, etc.), if the value of what you speculated on doubles, then sell half of it and hold the other half for the long term.  (You will actually need for it to rise a little more than double - you want it to rise enough that you get your initial investment back after you pay the transaction fees and costs - I'm going with "double" here to generalize the example).

When you get your initial investment back, you can do the same again with some other asset (or asset class).  If it doubles too, then you do the same thing again.

What you get left with is a bunch of assets that you haven't paid for.  After you get your initial investment back, you're gambling with the House's money.

In a similar vein, if you've ignored the asset and it's suddenly 5x what you paid for it, you can sell 1/5 to get your original investment back (or you could sell 2/5 and start your next phase with twice your initial investment).

There are other corollaries as well.

This leaves two problems.

The first is if the initial investment never doubles.  You'll have to bring other resources in if you want to gamble some more.

The second problem is "When do I sell these leftovers?".  This part is easier than you might think.

Chart the daily closing price for the asset for one year.

Chart the uptrend and/or the downtrend for the closing prices.

When the daily closing price drops down below the uptrend line, it's time to sell out and close out the position.