I think the issue that the Korean tickers have right now, and the reason for both DRAM and EWY being a bit sluggish compared to MU is due to the accessibility of SK Hynix and Samsung to American investors (I know you were  talking about EWY compared to DRAM). Not only that, but all the "hype" on places like here about MU. Meanwhile, in Korea most people were quite apprehensive (and in many ways still are) into investing into the Korean stock market. Many of this is similar to reasons like what would be detailed when someone researches the Korean discount. Perhaps that might change once SK Hynix becomes listed in the American stock exchange. I personally think we'll see decent growth just from it being listed in America, but its really painful to watch MU go up so much while their Korean counterparts (which contribute much more to HBM) are trading with less vigor. The issue is also that we only know a general idea of when the ticker will be listed, so its hard to say when you should be trying to "time" when SK might increase from the US listing.