The Financial Post reports in its Friday edition that exchange-traded-fund providers are starting to push at the limits on holdings of hard-to-trade assets as they try to give retail investors access to hot private stocks and debt. A Financial Times of London dispatch to the Post says that two U.S. ETFs have built up exposure to Elon Musk's unlisted rocket company SpaceX that exceeds the Securities and Exchange Commission's 15-per-cent limit on illiquid securities. An ETF run by State Street launched last year with the intention of having exposure to private capital of up to 35 per cent. A number of other funds have loaded up on unlisted shares in Mr. Musk's start-up XAI -- which was recently bought by Spacex -- as well as AI group Anthropic, defence tech company Anduril Industries and data analytics company Databricks. The purchases come as fund groups race to open up private company assets to retail investors who hope to access fast-growing companies that are choosing to stay private for longer. "We are seeing ETFs push the boundaries on the SEC's rules," said Bryan Armour at Morningstar. "We are not seeing the SEC push back on this at all, so it's not unreasonable to expect to see more ETFs pushing the envelope."