"Looks like a spike then back to reality, but up generally." I think you might be looking at a one day chart. Please go to your same yahoo finance link, and look at the 5 year chart. The stock was bumping along around 20 TWD for 5 years paying a regular small dividend, and then over the past couple of weeks has climbed up to over 30 TWD on unusually high volume and is still there. I think there may have been some sort of event or rumor that kicked it off rather than a change in public habits over the course of the year. If SYM traded on the New York Exchange, there would be a dozen news stories with the explanation, but it is hard to find news from the TW exchange. Has anyone been able to find a recent news story about SYM? I keep thinking they might have bought a company, sold assets, or are a takeover target.. something like that..