Accurate, but not asymmetrical. It's perfectly symmetrical: purchase of an asset for resale has a loss floor and no gain ceiling, sale of an asset (including short sales) has a gain floor and no loss ceiling. For actual transactions in either direction, there is a practical maximum gain/loss, even when there's not a theoretical one: if a value goes too far out of modeled range, one of the parties will abrogate when not able to pay the ludicrous amount.

For smaller investors making short-term trades (which is illegal if one has inside info, and unwise if not), generally Call or Put options are used. The constraints of payout/loss can get quite complicated fairly quickly by mixing different strike and maturity options.