short selling, page-34

I've got no problem with shorting - "buy low, sell high" is my motto - in no particular order.

However, I would like to know whether the market is symmetrical with regard to leverage. What I mean is that aggressive shorting can be used to trigger margin calls, leading to distressed selling and a quick buck for the instigator. Is there a comparable mechanism on the long side? That is, if you have borrowed stock to short and there is aggressive buying which pushes up the price, does the lender trigger a margin call forcing the short party to buy?

It seems to me that would be an important balancing factor in the market.

Jim.