Fund picks and pans stocks

Stush says:

Simple answer is that day traders can’t move the market. This is for two main reasons; First, that they deal in such tiny amounts of money and, second that they are unlikely to trade with the momentum of the market as they cannot compete with the major banks and brokerages on news supply and access to market analysts and leaders.

There is no obvious way to see the number of day traders putting on positions in a market, but you could try to assess the volume of day trades by comparing brokerages that deal in retail investors versus institutional brokerage firms.

Atheism's Advocate says:

Day traders keep the market running efficiently. Without them, the market would be very inefficient. Of course, the long-term buy and hold investors yield more on average than the day traders (simply because the day traders pay more commissions on average) but nevertheless, day traders are an essential part of our modern day market system.