WHAT’S GOOD for Elon Musk is not necessarily good for investors in Tesla stock. Or, is it? Munch this: the stock jumped 148 per cent from $408.09 on November 16, 2020 to $1,013.39 on November 15, 2021, on the NASDAQ. This jump masks a nuance: $1,013.39 was a 17 per cent slide since November 5. On November 7 (Sunday), Musk’s legion of Twitter followers responded to his ‘poll’ on whether he should sell 10 per cent of his Tesla holdings. The answer was a resounding yes (58 per cent), Musk promptly sold his stock the next day, and the stock promptly tanked. (The stock has since recovered to $1,096 on November 18.) The poll is a novel addition to Musk’s tweets on cryptocurrencies, whose values go up and down like…