The Round Trip Tax

Ask a trader how the month went and you get a story. Ask the wallet and you get a number. The gap between the two is usually not dishonesty. It is arithmetic.

Ten up, ten down, one percent gone

Take $10,000. Up 10% puts you at $11,000. Down 10% puts you at $9,900.

You are not flat. You are down $100.

Order does not save you either. Down first then up gives the same 0.99. The percentages are symmetric, the dollars are not, because the second move applies to a different base than the first.

One percent looks like a rounding error, so repeat it. Ten symmetric round trips leave you at 0.904 of where you started. That is down 9.6%, on a chart that looks like it went nowhere. Nobody made a mistake. Nobody got rugged. The path itself charged you.

This is usually called volatility drag, and it is the least dramatic way people lose money. It never shows up in a screenshot.

Getting back is harder than falling

The other half of the same fact is what a drawdown costs to undo.

• Down 10% needs an 11.1% gain to get even.
• Down 20% needs 25%.
• Down 30% needs 42.9%.
• Down 50% needs 100%.
• Down 80% needs 400%.

That last row is why one bad month can eat a good year, and why "I am up on the year" tends to come with an expiration date.

Which is why profit is a bad thing to save from

Any plan that starts with "I will save some of my profits" has a dependency problem. Profit is provisional. Until it has left the arena, it is a number that can still be revised downward by the next position. An unrealized gain is a rumor.

Volume is different. Volume is history. Once a swap has settled it cannot be un-traded, taken back, or marked down. It is the one number on a trader's screen that is finished.

That is why MORE meters savings against volume instead of gains. Not because volume measures skill. It measures nothing about skill. It measures something that definitively already happened, which makes it the only honest trigger for an automatic rule.

A floor, not a hedge

Be precise about what a skim actually does, because the overclaim here would be easy.

It does not beat volatility drag. It does not turn a losing strategy into a winning one. Nothing does that.

What it does is remove small pieces from the loop. A dollar sitting in a cash bucket has stopped round-tripping. It is not exposed to the next 0.99. It is not available to average down at 3am.

That is a floor, not protection. A Bitcoin bucket still falls when Bitcoin falls. A stablecoin bucket does not. The real difference between a savings bucket and your trading balance is not that one cannot drop. It is that you are not feeding the first one back into the machine every day.

Climbers do not get up a mountain by refusing to descend. They set anchors, so that when they slip, the fall has a bottom.

What it looks like in practice

A trader doing $50,000 of monthly volume at a 1% rate sets aside $500 a month. Across a year that is $6,000, out of activity that was going to happen anyway.

Green year or red year. The floor does not ask how it went.

The honest tradeoff

The slice comes out of the capital you trade with. If you genuinely compound your trading balance at a high rate, year after year, that slice has a real cost and you should size it accordingly. Set it at 1% instead of 3%.

Most accounts do not compound like that. Most accounts round-trip, and the arithmetic above is why. In that case the skim is not a cost at all. It is the only part of the year that survives it.