According to BlockBeats, the BitVol (Bitcoin Volatility) Index, launched by financial index company T3 Index in collaboration with options trading platform LedgerX, fell to 54.47 on July 28, marking a single-day decline of 11.79%.

The BitVol Index measures the 30-day expected implied volatility derived from the prices of tradable Bitcoin options. Implied volatility refers to the volatility implied by the actual prices of options. It is calculated using the Black-Scholes options pricing formula, which inputs the actual option prices and other parameters except for volatility (σ) to derive the implied volatility.

The actual prices of options are formed through competition among numerous options traders. Therefore, implied volatility represents market participants' views and expectations for the future of the market, making it the closest representation of the actual volatility at that time.