What a position costs to hold

Where the numbers come from

You supply the expense ratio and the dividend yield, because this site holds neither. Both are on the fact sheet or the statement you already have, and keeping them out of here is the same choice that keeps share prices out: the one input that would need a market-data licence is the one you type.

Nothing entered above leaves the browser. There is no request to make: the whole calculation is a handful of multiplications, and it runs where you are.

The one assumption

Three of the four terms are observable: the expense ratio and the dividend yield are published, and the commission is on your own statement. The fourth, the spread paid getting in and out, is not available from any free source at adequate quality, so it is a declared assumption with a liquidity-tiered default rather than an estimate dressed as a measurement.

Corwin-Schultz on daily high and low returned 23bp for Apple where the true figure is nearer 1bp, and zero negatives are clamped as the method requires. Free live quotes were worse: 447bp on a mega-cap, and a crossed small-cap book, being stale prints rather than the NBBO. It is also the least material term — about 3% of total cost over three years. Override it above if you know yours.

What this is not

Not a forecast. No view on where a price is going, no entry or exit timing, no probability of gain. A cost figure can be checked; a return forecast cannot, and that difference is the whole reason this is worth publishing under a name that says research rather than advice.