How do you calculate margin requirements on stocks?

The amount of Buying Power available for a given trade depends upon a number of factors including the product traded and the account type (e.g., Cash, Reg. T, Portfolio Margin). It is calculated by dividing the Equity with Loan Value…

Introduction

The methodology used to calculate the margin requirement for a given position is largely determined by the following three factors:…

Under SEC-approved Portfolio Margin rules and using our real-time margin system, our customers are able in certain cases to increase their leverage beyond Reg T margin requirements. For decades margin requirements for securities (stocks and options) accounts have been calculated under a Reg T rules-based policy. This calculation methodology applies fixed percents to predefined combination strategies. With Portfolio Margin, margin requirements are determined using a "risk-based" pricing model that calculates the largest potential loss of all positions in a product class or group across a range of underlying prices and volatilities…

The maximum leverage offered for fixed income products depends upon a variety of factors, including the market, any regulatory minimums required by the exchange or its primary regulator, the margin methodology available (e.g., Reg. T and Portfolio Margin for IB LLC clients) and any house margin requirements imposed by IBKR…