(Image credit: ANGELA WEISS/AFP via Getty Images) SpaceX and OpenAI are gearing up to go public in what would be the biggest initial public offerings (IPOs) of all time, and Nasdaq ( NDAQ ) can hardly wait. The exchange operator rolled out new "fast entry" rules that will allow it to speed up the process of adding such massive companies to its flagship Nasdaq-100 index. Ordinarily, it can take up to a year for a mega-cap stock to be included in the Nasdaq-100. Under the new rules (PDF), which go into effect on May 1, newly public mega caps would be eligible for inclusion after just 15 trading days – and with only five days of prior market notice. From just $107.88 $24.99 for Kiplinger Personal Finance Become a smarter, better informed investor. Subscribe from just $107.88 $24.99, plus get up to 4 Special Issues CLICK FOR FREE ISSUE Sign up for Kiplinger’s Free Newsletters Profit and prosper with the best of expert advice on investing, taxes, retirement, personal finance and more - straight to your e-mail.…