
Understanding Buying Power Fluctuations in High-IV Stocks Like NVDA (v.s. AAPL and GOOG)
Overview Selling short puts on AAPL, GOOG, and NVDA with similar expiries revealed a practical difference:NVDA’s buying power (BP) requirement tends to move intraday, while AAPL and GOOG remain comparatively stable.This article explains why—contrasting Reg‑T with risk‑based (portfolio) margin, walking through a worked example,and showing how BP reacts to implied volatility (IV). 1) Margin Models…




