This drove silver prices through the roof. For the scheme to work people would have to invest in silver at those prices (believing it would continue to become more valuable / more scarce) so that the Hunt brothers could progressively sell off their silver at the inflated prices.
Everyone called them on their bullshit and the price of silver normalized. They pledged collateral in their various investments to back this gamble, they lost an estimated $4 billion when everything was said and done.
Sorry to go a bit off topic but that's not quite how it happened.
The Hunt Bros were ostensibly buying silver because they had no faith in fiat currency. They never sold silver or silver futures even when the price was peaking. Although they did contract to purchase much more silver than they could afford, so logically at some point in the future they'd have had to sell contracts one way or another.
They didn't lose money because "everyone called them on their bullshit". They lost money because COMEX and CBOT board members (i.e., the guys who control the trading rules) abused their position of power to suddenly change the trading rules... specifically, to destroy the Hunt Bros (and conveniently to enrich themselves).