What crossing the spread costs, name by name

Module 2 taught the spread as a percentage. This lesson multiplies it by your position, because costs are paid in money, and the range across names is the widest on the platform.

The arithmetic, tier by tier

A 500-share position at £4.00 is £2,000. In a megacap quoting a 0.2% spread, the full round trip costs £4 - a rounding error. The identical position in a small-cap quoting 6% costs £120 on the same arithmetic - 6% of the position gone before anything moves, a hurdle most trade ideas cannot clear. Same exchange, same order ticket, thirty times the cost: module 1's hundredfold liquidity range, arriving on the invoice.

Half now, half later, all real

• Entering at the offer pays half the spread against the mid; exiting at the bid pays the other half - the round trip pays the width.
• Limit orders can earn the spread instead of paying it - at the price of maybe not trading; the choice between paying for certainty and being paid to wait is an execution decision this platform describes without prescribing.
• The profile matters as much as the quote: module 2's open-auction width and news-stretch mean the same name charges different spreads by hour - timing an entry into calm hours is a real cost reduction, free of any forecast.

The standing habit

Before any equity trade: position value times spread percentage, at the hour you will actually trade. If that number is a meaningful share of the idea's target, the idea has a cost problem no analysis fixes - the same gate every track has installed, with equities' twist being how violently the answer swings between names.