I wonder if the other factor besides interest rates is the prevalence of algorithmic trading.<p>When I see these swings and I hear these &quot;flash events&quot; it reminds me of extremely fast decisions made by machines based on very small changes.<p>I&#x27;m curious is there an index where we can see how much trading happens almost unattended on a daily basis via algorithmic systems?  I wonder how that would map against the last decade of &quot;systemic changes&quot; in markets?