SpaceX stock was priced at $135 and later reached a closing high of $201.80. SpaceX Share Price Since IPO BarchartA Thin Float Cuts Both Ways SpaceX’s IPO put approximately 639 million shares into public hands. The 911.5 million shares eligible on Aug. 6 are roughly 140% of that original pool. S3 Partners estimated that 219.3 million SpaceX shares were sold short as of July 29, equal to approximately 34% of the float and worth $24.6 billion. S3 estimated that only about 40 million SpaceX shares were sold short on June 23.