◇ GLOSSARY
Perpetual futures (perp)
A derivative contract with no expiry date. You hold price exposure to the underlying without owning it; funding payments keep the contract near spot. Unlike a quarterly future, you do not roll or take delivery unless you close into spot elsewhere.
A perp is not a loan to buy BTC and not a share of Coinbase stock. It is a contract that reprices your P&L as if you held a fixed notional of the underlying, while funding shoves the contract price back toward spot every hour or eight hours.
That matters because every other mechanic hangs off it. No expiry means no roll calendar, but it also means carry never stops. Hold a $10,000 BTC perp long for 30 days at +0.01%/h funding and you can pay $720 on a flat chart. The product did exactly what it promised.
Perps win when you need levered delta for hours or days and you have modeled funding. They lose when you wanted spot with no schedule and picked the perp because the slider went to 20×. They are different products with different failure modes.