Perpetuals never expire — funding is the rent that keeps them tied to spot. Price what your hold actually costs (or earns).
Funding is exchanged directly between traders every 8 hours on the full position value, not your margin. A "small" 0.01% rate is 10.95% annualized — real money on any position held for weeks. When rates spike during euphoria (0.1%+ per interval), holding the crowded side can cost more than the move you are hoping for.
When the rate is positive, longs pay shorts (the perp trades above spot and the market pays people to short it back down). When negative, shorts pay longs. You pay or receive automatically every 8 hours while the position is open at the funding timestamp.
No — each exchange computes its own rate from its own perp-vs-index premium, and they diverge, especially on smaller coins. That divergence is what funding-arbitrage desks trade. Check the live per-exchange rates on the MarginPad funding page before choosing a venue for a long hold.
Close before the funding timestamp and you pay nothing for that interval — funding only hits positions open at the exact mark. Spot holdings never pay funding, and dated futures (quarterlies) replace it with a fixed basis, which suits long-term directional holds better than perps.
Free, no signup, runs entirely in your browser. Educational tool — not financial advice. Practice the setup risk-free on the MarginPad paper-trading terminal before putting real money behind it.