Why is Short Selling of Stocks Needed?

name just one that moves the market then please

Preception that interest rates will go up or down

a simple announcement from a big company that its earnings are going to be much higher can move the market up, as well as down if the other way. earnings move the market.

short selling is needed to keep the markets functioning properly. to be very liquid the market needs lots of ways to get in and out, and short selling is one of them.

the rise and fall of interest rates change the value of companies, as they need to borrow. when rates change it affects their bottom line. what makes the market move from interest rate changes is the effect it will have on earnings.

As I've stated on the Stock Market Forum many times, when the economic risk goes up (increased threat to future earnings) prices have to come down. The increased threat alone will cause prices to decrease and this is perfectly rational behavior by investors.