If you are bearish, buying a put is usually less risky than an outright short. Always remember that warrants expire. Such time decay becomes especially steep in the final month or so. A good way to reduce the effects of this decay is to never run them to maturity. You can lose the premium quickly if you get it wrong.
Warrant prices can fall to near zero very quickly, especially as expiry nears.
For options and warrants, price information is much poorer, and you will probably only be able to get the price from the site of the issuing investment bank or Net broker. One stock can have hundreds of options based on it, by put or call, expiries and strikes, and you will have to choose the one that best matches your expectations. Most covered warrant issuers guarantee a bid-offer spread, but you will often be surprised by just how far away the buying back price turns out to be when you and many others head for the exit door. And no time more than on option expiration days. Triple-witching hour in the US and, to a lesser extent, the Special Quotation in Japan is where all the large practitioners try to manipulate underlying stock prices to ensure that as many or as little as possible stock options expire favorably to them.