Why it happens
Some sites are not funding businesses at all. They are collecting contact details and selling them, sometimes to a dozen buyers at once, sometimes repeatedly over months.
You cannot tell from the form. A lead-selling page and a genuine marketplace look identical, because the difference is in what happens after you submit rather than in what you see.
This is why the volume arrives all at once: a dozen buyers all received your number within the same minute.
The question to ask first
“Is my information sold as a lead, and how many parties will receive it?”
A genuine marketplace can tell you exactly: your file goes to the funders who write your industry, state and revenue band — a specific, small number, and not to anyone else.
A vague answer, or an answer about ‘partners’ without a number, is the answer.
Other signals worth reading
Does the site say plainly whether it is a lender or a broker? Ambiguity there is deliberate.
Does it state costs anywhere, in dollars? Sites that intend to sell you on rather than fund you rarely do.
Does it ask for a phone number before telling you anything useful? The order tells you what the page is for.
If it has already happened
Ask each caller where they got your details and to remove you. Under the TCPA a request to stop must be honoured.
Register with the National Do Not Call Registry, though it has limited effect on business-to-business calls.
The calls typically taper over a few weeks as the lead ages and stops being resold.