Are you still flame baiting? One more time and I' make you disappear from the forum for a while.

What you are trying to say about short selling is applicable to commodities and stocks where there is a value to the goods that you are short selling.

For example, if you buy 1 unit of stock that is USD100... and it goes to zero, your losses are limited to USD100 from the beginning. However, if you short sell USD100 of stock, in theory, the price of the stock can go up to unlimited which is why the posting says your losses could be unlimited. If the stock goes up to USD1000 you have lost USD900.. or if it goes up to USD10000 you have lost USD9900.

As for currency, the risk is still there but on a more limited scale where the risk is similar to whether you are buying or selling a currency. Unless something disastrous to the country, the currency will not rise/fall uncontrollably. That is the reason why we trade in major currency and not the exotics ones. Imagine if you traded in the Venezuelan bolívar, you'd either be a very rich man or a very bankrupt one.