In principle i agree, the hard part is always to catch the right moment... For selling the rumour the right time would have been early May at 20$, when everyone expected a further rise to 35... And can you time exactly when to get in? When things have settled and mainnet you might be well too late... As @zoidsoft wrote earlier, do you know where to buy mainnet eos in the early days. Remember segwit and the 2x disaster that ensued, did it harm the btc price? For that reason I d say it's more effective to try get in early after due diligence and then hodl...