Mainly large accredited investors, and institutional investors like banks. However, only about $3 trillion is allocated total to hedge funds. Which is roughly 1% of total assets held be banks.

So, if those banks invested solely in funds that were 100% in PR bonds, their total liability to those funds would be only be about ~1%. Or, about .00005% of total liability. I might have added or subtracted a zero, but the PR debt is only like $40bn, which is spread throughout thousands and thousands of investors and funds or whatnot. It's such ridiculously low exposure that it's pretty much not a big deal in the grand scheme of things.

Just for example, Detroit's bankruptcy was $18bn. About 1/2 of what PRs is. This really won't affect a lot of people. And, probably affects less smaller investors than Detroit did, seeing that municipal bonds tend to have a lot of local investors, and are a bulk of investments held by pensions and other public investment vehicles. Whereas PR debt was so shitty, only those who could afford higher risk would purchase in bulk.

Either way, the crazy thing about a default is that they will still pay, they will pay until they can't pay, they will pay even small amounts. At this point, it will go to court, and the court will force PR to start selling assets to pay off their obligations, and will order most available funds to be diverted to paying off those obligations. This is significantly different than a bankruptcy, where bankruptcy would protect assets, a default is a free for all over assets. In the end, most investors will get some of their money bank, some might actually make a profit over the original purchase price.

Really, the only people that are going to be hurt by this the most, are public sector employees in PR, who have a significant chunk of their pensions and retirement plans invested in PR debt, as it was pretty much 100% tax free for them to invest in. And, seeing that it was mainly shitty government policies that gave their government employees lavish pensions at the sake of their own economy, not too many fucks will be given, seeing that it's going to be mainly government employees reaping the consequences of their inept government polices. Going from other examples, government pensions will be the absolute last to get their cut of the money, if any.