What happens if both sides just stop responding after signing an LOI?

In practice, most non-binding negotiations end exactly this way — quietly, without either side formally terminating anything, once neither party is actively pushing the deal forward. Since the core deal terms in a typical LOI aren't binding, going quiet doesn't itself breach anything; there's usually no legal requirement to formally cancel a non-binding negotiation for it to be considered over.

What doesn't quietly disappear, though, are any specific provisions your LOI made binding regardless of the rest of the document. If it included a confidentiality obligation, that generally continues to apply to information already shared, whether or not anyone is talking. If it included an exclusivity clause with its own defined period, that period still runs its course on its own terms even during silence — it doesn't end just because communication stopped, unless the clause itself was tied to ongoing activity.

Before assuming a lapsed conversation means every obligation has lapsed with it, check what your LOI actually made binding and whether any of it survives independently of active discussions. A Treadstone business lawyer can confirm what, if anything, is still live.