When you go long and buy a stock....RVX or any other, so long as its held in a marginable account, then your broker can make money by loaning out your shares to someone wanting to sell them. If your shares are in a registered account however, like a TFSA or RSP account, then they're not available to be loaned out.

Remember, you don't actually have physical possession of your shares in almost all cases. They are held by your broker "in street name". So lets say you have 100,000 shares of RVX in a non-registered..."open money" account. A short seller will ask your broker if he can borrow 10,000 shares, for which the short seller will pay a fee.....perhaps $50.

Now the short seller sells the 10,000 shares he just borrowed....and to keep the math simple we'll say he sells them for $2 per. So the short seller has just netted $20,000 for the sale of your shares....but he will, at some point, have to replace the shares...unless RVX is delisted.

The $20,000 will be held in the short sellers margin account....plus a premium in case RVX suddenly takes off, with the PPS being less than $5 (a penny stock) the margin requirements are likely to be in the neighbourhood of 250%. In other words the short seller will need to have around $50,000 in his margin account with RVX trading around $2. If the PPS drops all the way to $1...then the short seller's margin requirements drop and he'll only need to have $25,000 or so in his margin account.

The short seller makes money when he's able to buy back the shares lower than what he sold them at. So if he borrowed and sold 10,000 shares at $2 netting $20,000 and then is able to buy them back for $1 per....then his profit is $10,000 less brokerate fees.

As for preventing your shares from being loaned out.....one way is to keep a sell order in for them. Right now we're trading around $1.60 so a sell order say for $2.10 would likely be accepted by most brokers and would prevent your shares from being loaned out.

Another way is a certificate call.....I've seen cert calls a number of times, but honestly I think they're a load of crap 99% of the time. The idea is that, by asking for physical delivery of the certificate for your shares....that shorts will be required to buy. Typically you'lll see a cert call when short interest is very high....a lot higher than what we've seen with RVX.

There are a lot of nuances, one of which is naked short selling. Short sellers are supposed to engage in something called "positive determination"....before borrowing shares and selling them they're supposed to make sure there are shares available. Naked shorting is when a stock is sold short despite the fact that there are no shares available. In the US they have a regulation called SHO, (I forget what is stands for) and they publish a list of stocks that have naked short positions. MM broker dealers are allowed to naked short as part of their role of ensuring liquidity.

Anway...that's a bit of a primer. Clear as mud?