[Algorithmic trading, which is done by computers, can buy and sell stocks in huge quantities in microseconds. This is where the concept of flash crashes comes from. These aren’t done by humans, but by computer algorithms that have been programed to watch news sources for key indicators and then act on them. Believe it or not, those microsecond buy and sell orders are very profitable for the owners of the algos (banks) and the idea of charging a tax is to stop this from happening.]
The flash crashes don’t bother me. Eventually, value seeks its true level, determined by company revenues, profit margins, balance sheets and returns on equity.