You've got quite a toolkit if you're serious about measuring market volatility. Here's what traders typically work with:

• Standard Deviation – the classic baseline
• Hodges Tompkins – adds some refinement to the basics
• Rogers Satchell – handles gaps differently
• Garman Klass – incorporates high/low data
• Yang Zhang – combines multiple price information sources
• Parkinson – focuses on the extremes

Each method captures volatility from a different angle. Some factor in opening and closing, others lean into intraday ranges. It's not just picking one and forgetting about it – traders often cross-reference multiple estimators to get the full picture of what the market's actually doing.