The Korean won is the latest example of that

Yesterday, in early Asian trading there was news rumoured to be saying that South Korean officials are looking into measures to combat the KRW strength.

Then, Bank of Korea governor came out with a "warning" saying that they're watching the FX market closely. And he even reiterated that stance again today here.

But despite all of that, the KRW is set to end the day 0.23% higher against the USD. And in fact, whatever drop in the KRW following intervention talks have all been recovered in trading today. Although the dollar did give up some overnight gains, you would think central bank "intervention" should outweigh that, no?

The Korean won gained 12.8% against the US dollar in 2017 - being the top performing currency in Asia.