Billionaire Elon Musk responded to singer Billie Eilish after she called him a "coward", among other insults, for hoarding wealth. Musk wrote, "She's not the sharpest tool in the shed." Eilish's post came amid news that Musk could soon become world's first-ever trillionaire. Eilish made news after urging billionaires to give their money away for good during an award show.