Knowing what your coins are worth is easy. Knowing whether you are actually up is not, because it depends on what you paid, and most people bought in pieces at different prices.
This page explains how Moonitor calculates profit, and how to record transactions so the result is meaningful.
Every figure discussed below appears on this screen: what you put in, what it is worth now, the difference, and the average price you paid.
Record buys individually
The single most useful habit: enter every purchase as its own entry, with the amount and the price you paid.
It is tempting to keep one line per coin and adjust it as you go. That works until the second purchase, at which point you are doing the averaging by hand, and any mistake is invisible because the app has no way to check your arithmetic.
With individual entries, Moonitor derives everything else.
Weighted average buy price
Your average buy price is not the average of the prices you paid. It is weighted by how much you bought at each.
Buy 0.1 BTC at $30,000 and 0.9 BTC at $60,000, and the naive average is $45,000. The weighted average is:
(0.1 × 30,000) + (0.9 × 60,000) = 57,000 total cost
57,000 ÷ 1.0 BTC = 57,000 per BTCThe real figure is $57,000, because most of your money went in at the higher price. The naive number would have you believe you were profitable at $50,000 when you were down badly.
Moonitor divides your total purchase cost by your net quantity, so this is handled for you.
Net cost and market value
Two numbers drive the profit figure:
- Net cost is what you have put in, after accounting for sales
- Market value is what your holdings are worth at the current price
Profit is the difference, and the percentage is that difference over net cost:
profit = market value − net cost
profit % = (market value − net cost) ÷ net cost × 100This is unrealised profit. It is what you would have if you sold everything right now at the quoted price, before fees, spread and tax.
Recording sells
Mark a disposal as a sell rather than deleting the buy it came from.
Deleting destroys the history. If you bought 1 BTC and sold 0.5, deleting half the original entry leaves the app thinking you only ever bought 0.5, and your cost basis and profit are both wrong from then on.
Recorded as a sell, the quantity is subtracted from your position while the original purchase cost stays in the record, so the cost basis of what you still hold remains correct.
What these numbers are not
Worth being explicit, because portfolio profit and tax profit are different things:
- Fees are not included. Trading fees, withdrawal fees and network fees all reduce real returns and none of them appear here.
- This is not a tax calculation. Tax regimes use specific cost basis methods, FIFO, LIFO or average cost depending on your jurisdiction, and they care about realised gains on disposal. Moonitor shows a weighted average of your holdings, which is a portfolio view, not a tax one. For a tax filing you want dedicated software or an accountant.
- The price is a quote, not a fill. Your total uses the current market price. Actually selling moves the price, especially in a thin pair.
- Only what you enter is counted. Airdrops, staking rewards and forks do not appear unless you add them, and if you do add them, the cost basis you assign is a judgement call.
Denominating in Bitcoin
A portfolio can be up in dollars and down in Bitcoin at the same time, which is the more relevant comparison for many people. Switching the denomination recalculates profit against BTC instead. See track your portfolio in Bitcoin.
