What trading actually costs

Every real trade pays two costs most beginners never see itemized: a fee and the spread. Both are small on any single trade, which is exactly why they matter — they compound with every round trip.

The fee is what the exchange charges to execute. At major US crypto exchanges, entry-level “taker” fees run around 0.4% to 0.6% of the trade's value. Aureus charges a 0.40% practice fee on crypto trades, taken from your practice cash as its own labelled line — modelled on the real thing so the arithmetic you practice is the arithmetic you'd meet.

The spread is the gap between the highest price buyers are offering and the lowest price sellers are asking. A real buy fills at the higher side; a real sell at the lower. Crossing it costs money even when no fee is charged — it's how “zero-commission” trading is never quite free.

Aureus deliberately does not model the spread, because we have no honest bid-and-ask source to model it from — and the trade ticket says so. So a real trade costs more than a practice one, beyond the fee. A strategy that only just breaks even here would lose money crossing real spreads.

Frequent trading multiplies both costs. Ten round trips pay the friction twenty times. How often you trade is your call. Practice shows the cost so the arithmetic is the real one.