I too only invest, not sell short. In fact, I don't think that...

I too only invest, not sell short. In fact, I don't think that short selliong should be permitted - if people want to profit from an expected decline in share price, they should use a derivatives market.

The reason I don't think that short selling should be permitted is that in share market investment - real investment not gambling - a measure of underlying share value is market cap (# of shares * share price) vs business profit and prospects. When someone short-sells, extra shares come into the market. The number of people 'owning' shares increases, and consequently the number willing to buy the real shares is reduced. ie, short-selling has the effect of manipulating the market in its own favour - it manipulates the market share price downwards.