June 18 (Reuters) - Shares of Elon Musk's rockets-to-AI firm SpaceX SPCX.O dropped nearly 9% on Thursday, as the post-IPO frenzy that briefly placed it among the top five most valuable companies of the world appeared to fizzle out.

Its shares were last down 8.8% to $174.8, after falling nearly 5% in the last session. Despite the losses, the stock still traded more than 29% above its $135 offering price.

Earlier this week, the market capitalization of SpaceX overtook that of Amazon AMZN.O, momentarily even surpassing that of Microsoft MSFT.O.

Bloomberg News reports on Thursday that SpaceX bankers were preparing for a bond sale of at least $20 billion. SpaceX also said earlier this week that it is buying Anysphere, the startup behind the popular AI coding agent Cursor, for $60 billion in an all-stock deal.