Weekend holding is the question of whether your positions may stay open from Friday's close to Monday's open. Markets are closed over the weekend, so news can pile up and prices can reopen far from Friday's close. That gap is risk the firm cannot control, which is why some firms close your positions for you on Friday and others let you hold.
Firms handle this differently. Some plans force a Friday close: Ment Funding, for example, closes positions at 3:45pm Eastern. Other plans allow weekend holding outright. The rule may also differ between the challenge and the funded stage, or between asset classes on the same plan.
This matters most for swing traders, whose whole method depends on holding for days or weeks. A swing strategy cannot run on a plan that closes everything on Friday, no matter how good the rest of the terms look. Day traders, who close out daily anyway, are barely affected.
The common trap is forgetting the Friday close time. A trader who opens a swing trade on Friday afternoon can find it closed by the firm within the hour, at whatever price the close executes. Check the Friday close time and the weekend rule on the plan page before you commit to a swing method. Prop trading can cost you every fee you pay.