It depends on what you mean, do you mean both gross and net? Just one of the two?

Gross margin of zero would be mean you sell at exactly the cost to produce. Net margin of zero means you cover all your expenses including COGS. The only really difficult, practically impossible, thing would be doing both at the same time. Though, I could also see a case where you drive down net margins once sunk costs are paid and achieve both.

Doing so practically, or sustainably, in most circumstances would be uhh crazy… but it’s not impossible. Even then I think aiming for zero margin is a pretty credible tactic in eliminating competition if you can out sustain them.

TLDR; Weird? Sure. But not impossible. And even sort of likely if you’re trying to atrophy your competition out of existence.