OppenheimerFunds among the biggest bulls on Puerto Rico's municipal bonds

Puerto Rico's missed debt payment on Monday is seen by some on Wall Street as just the latest shoe to drop for the financially-strapped island nation. The country has another $2 billion debt payment due July 1, is $70 billion in debt, and is prevented by U.S. law from seeking protection through Chapter 9 bankruptcy that is available to most U.S. municipalities. The default on a nearly $400 million debt payment is expected to ripple across the municipal bond markets, and could create some awkward moments for financial advisers that are allocating clients to seemingly plain-vanilla muni bond funds. In essence, because of Puerto Rico's triple-exemption status, which means the income on its bonds are exempt from taxes at the federal, state and local levels, some municipal bond shops have been loading up on the country's higher-yielding debt. Of the muni bond funds tracked by Morningstar Inc., OppenheimerFunds stands out as the biggest fan of Puerto Rican bonds.