Wasps have enough financial backing to compete next month, which allows them to finish their Aviva Premiership season, but the club need urgent investment to remain in business beyond May.
Wasps are in danger of going into administration after a takeover deal fell through last week but Rigby is expecting the club to find new investors.
"We have had quite a variety of approaches, from traditional investors to people who manage money on behalf of wealthy individuals," Rigby told the Telegraph.
"I do believe, with the interest that was already there and the new interest that has emerged, it will come together and produce a successful sale."
Wasps sit 11th in the table, four points clear of danger with a game in-hand.