A new buyer has emerged in the $8.6tn US market for corporate debt in the years since the financial crisis. It is not a hot new hedge fund or traditional asset manager on Park Avenue. Instead it is the very sellers of these bonds themselves: companies such as Apple, Microsoft, Amazon, General Electric and Ford.

Together, 30 US companies have amassed a portfolio of cash, securities and investments worth more than $1.2tn, according to a Financial Times analysis of filings with the Securities and Exchange Commission. The figure dwarfs the holdings of some of the country’s largest asset managers and has made the likes of Apple, which holds more than $150bn-worth of corporate debt itself, investment managers in their own right.

As cash piles have grown, these companies have ventured into riskier corners of financial markets, investing in corporate and securitised debt. Some have established their own trading desks and now run multibillion-dollar lending operations, businesses typically left to financiers on Wall Street. Others outsource that work to established portfolio managers.