"However, SEC mandated reforms were implemented at the time which further restrict the type of investments the retail funds can make. Many (most?) became government-backed money market funds. These changes made the retail funds much less profitable."
Brokerages and mutual fund companies seem to have done their best to confuse matters. They certainly made it appear as though people were being forced to accept lower returns.
If you were already investing in a US Treasury fund (e.g. PRTXX) or a US government fund (T. Rowe Price did not have one), nothing changed. If you were invested in a prime fund (i.e. one that could invest in corporate paper and other non-US government securities), things may have changed.
Financial institutions were reluctant (perhaps prohibited, I'm not sure) to allow you to use a fund that could freeze redemptions as your core/transaction/checking account. So they had two choices - convert their "core" fund offerings from prime to government, or require you to pick a different fund (a government fund) as your core account. They went with door number 1.
TRP changed Prime Reserve to Government MM (PRRXX), Fidelity changed Cash Reserves to Government Cash Reserves (FDRXX), etc. But T. Rowe Price also did something else. It took its high minimum (higher yielding) retail prime fund, Summit Cash Reserves, lowered its min to $2
500 (dropping the "Summit" high min part), and renamed it Cash Reserves (TSCXX). So one still had a prime fund available; arguably a better one than Prime Reserve.
Here's T. Rowe Price's description of the changes required and what it did:
https://www4.troweprice.com/mmr/content/dam/money-market/articles/MMF Reform_US_04-12-2016_Update_v2.pdfTSCXX wasn't forced to change anything. Here are the portfolio compositions as given in the
April 2014 and
October 2017 reports.
Security Type 2014 2017
Commercial Paper 53% 52%
Muni Obligations 28% 23%
Foreign CDs (USD) 7% 5%
Treasury Notes 6% 9%
Domestic CDs 5% 3%
US Treasury Bills 1% 4%
Other (net) 0% 4%