BOSTON (Reuters) - Investor David Einhorn said on Thursday that prominent venture capitalist Chamath Palihapitiya and entrepreneur Elon Musk threw "jet fuel" on the GameStop Corp trading frenzy in January when the video retailer's shares rose by 2,000% and later prompted a hearing in U.S. Congress. Einhorn, who runs hedge fund Greenlight Capital, also said U.S. lawmakers seeking answers to how day traders were able to wrest control of GameStop's share price from established hedge funds should probe regulators instead of investors.