WASHINGTON (Reuters) - The chairman of the U.S. Securities and Exchange Commission on Thursday said special purpose acquisition companies (SPACS) offer “healthy competition” to traditional public offerings, but only when sponsors and investors have access to adequate disclosures. “To the extent that a SPAC structure is an alternative to ... a traditional IPO, in some ways it’s very healthy,” SEC Chairman Jay Clayton said in an interview on CNBC. “It comes down to a question about disclosure and transparency and whether investors are getting all the information they need.” Also dubbed “blank-check” companies, SPACS are shell vehicles with no pre-existing assets which are initially valued based solely on the amount of cash they raise, which is then used to buy up assets. Retail investors who buy into SPACs pay the same price as big Wall Street investors, but may have little knowledge about potential acquisition targets. In contrast, big SPAC investors, which provide the bulk of financing, are typically given confidential information on the vehicle’s strategy. Clayton’s remarks on Thursday followed reports that electric-truck maker Nikola Corp, which initially raised money as a SPAC, is being investigated by regulators. Clayton said on Thursday that the agency would be keeping an eye on the quality of disclosures. “People should understand that the compensation structures and the motivations here may be different than they usually expect ... but we will be paying attention to what’s happening in the market,” he said without elaborating.