Allenhobbs has a lot of experience with warrants. Maybe he'll show back up to offer some insight. He spent a little time in the clinker this weekend. Amazing what you can dig up just by having someone's real name.
i do. i trade mostly exotics available in europe. from my point of view they are an interesting vehicle with good liquidity and very inexpensive to trade when doing size. imo the key differentiator of the exotics i trade is their leverage. it is frequent to spot warrants that offer 200X leverage with close to 100 deltas, thus one gets a huge bang for the buck. citi is a market maker on some of the markets in europe. here's the link to their warrants products. https://citibankinternational.co.uk/uk/EN/index.asp?pageid=31