Wall Street has a new nickname for its latest anxiety attack: the "SaaSpocalypse."

According to CNBC, software stocks saw massive moves in both directions this week, as investors tried to work out which companies are best insulated from artificial intelligence. The debate, CNBC reports, is intensifying — and the swings have been wild enough in both directions to suggest the market has not settled on an answer.

The term is a play on SaaS, or "software as a service" — the subscription model behind most of the business tools companies rely on, where customers pay a recurring fee per user for access to software running in the cloud. That model has been one of the most reliable money-makers in tech for two decades, which is precisely why a threat to it rattles investors so much.

The unease traces to a straightforward question with no clear answer yet: if AI systems can generate or replace some of the work that software subscriptions currently handle, what happens to the companies selling those subscriptions? Some investors are betting certain names get disrupted. Others are betting the same technology makes established software firms more valuable. This week's trading suggests both camps are moving money aggressively, and the sharp reversals in both directions reflect a market sorting winners from losers in real time rather than a uniform verdict on the sector.

It's worth being precise about what is and isn't known here. The reporting describes volatility and an unresolved argument — not a confirmed collapse in software business models, and not a verdict on which companies are safe.

Why it matters: software subscriptions underpin a large share of the tech sector's value and sit in countless retirement portfolios and index funds, so a repricing of which of those businesses survive AI would reach far beyond the people arguing about it on trading desks.