Of course you should always take Haejin's posts with a pinch of salt. As with anything in Steemit that gas titles like "imminent 300% gains". It's pure clickbait, in this case, it's pure "UpvoteBait" and it's not hard to figure why :)
When crypto is on an uptrend it makes sense to listen to Haejin's opinions but always stay on the backfoot because this is crypto!