New York, June 5 -- In a major setback for SpaceX, the S&P has ruled out changing its existing rules for entry of megacap companies into the benchmark index.

S&P Dow Jones Indices confirmed that exceptions to its seasoning and profitability rules for megacaps won't be made effectively blocking an early entry for Elon Musk's rocket startup, according to a CNBC report.

SpaceX is raising $75 billion and targeting a valuation of $1.75 trillion. At this valuation, SpaceX would be placed among the top ten most valuable companies listed in the US.

However, S&P Global said that rules governing entry to its broader S&P Total Market Index and Dow Jones US Total Stock Market Index would be modified making it easier for SpaceX to be listed on thes...