On Fidelity, not every account type has access to those high yielding core positions (I don't know why). But you can choose to invest your cash directly into t

On Fidelity, not every account type has access to those high yielding core positions (I don't know why). But you can choose to invest your cash directly into the high yielding money market funds by placing a trade. The relevant tickets are FDRXX and SPAXX. Do note that this is different than changing your core position.