Jim Cramer warns this overlooked danger could threaten the market rally

• CNBC’s Jim Cramer warned that a flood of massive IPOs and capital raises could drain money from the stock market, threatening its rally.
• Anthropic’s highly anticipated IPO filing on Monday came after companies have already raised $148 billion through public offerings this year, raising concerns that investor demand may struggle to keep pace with new stock issuance.

CNBC's Jim Cramer warned Monday that a wave of massive initial public offerings and capital raises could threaten the bull market.

Anthropic, the company behind Claude, filed its IPO prospectus Monday, moving one of Wall Street's most anticipated public debuts a step closer. Investors have long awaited public offerings from AI leaders Anthropic and OpenAI, but Cramer said that their potentially massive fundraising needs could strain an already crowded market. With $148 billion raised through IPOs so far this year, he fears the influx of new shares could outstrip investor demand and derail the rally.

"Politics can weaken the bull, higher rates can choke it, but if you want to slay the darn thing, use the IPO lance and stab it again and again," the "Mad Money" host said. "It just gets weaker and weaker until it is weak enough to be slaughtered with the ease of a bad quarter, a rate hike and a run on the margin bank."

Cramer emphasized that his concerns aren't about the viability of AI itself. Unlike the speculative internet startups that collapsed during the dot-com bust in 2000, many of today's leading technology companies have established businesses and genuine demand for their products.

"This time around the companies are real. They tend to make big money. We trusted them before this moment. We will trust them after," he said.

But Cramer sees one troubling similarity between the two periods: the enormous amount of capital being raised. During the dot-com boom, a flood of stock offerings eventually exhausted investors' buying power, contributing to the market's collapse. Supply outpaced investor demand.

He fears a similar dynamic could emerge as companies including Meta, Alphabet, SpaceX and Oracle tap capital markets. Cramer warned that these massive fundraising efforts could absorb investor dollars that might otherwise flow into the S&P 500 and other stocks, putting pressure on the broader market even as corporate fundamentals remain strong. Cramer's Charitable Trust, the portfolio run by CNBC's Investing Club, owns shares of Meta and Alphabet.

"I think both the debt and the equity markets are running out of money," he said.

That means the market could run out of the money companies need to finance their ambitions before investors see the payoff. "I am not calling a top," he said. "I am just saying that I do not like what I see."