📉 Phái sinh

Buying a share means owning something; opening a derivatives position means taking on an obligation that costs money every day until you close it. Notes on index futures from the builder's side: why margin here is a deposit against an obligation and not a loan, why profit and loss becomes real cash every evening, why the counterparty after matching is the clearing house — and what changes for a broker that must live with two counterparty models at once.