My aunt received 2 text messages from 29943:

FIDELITY: a rollover or withdrawal was initiated from your account. Not you? Please Call 800-438-2475. Reply STOP to opt out. Msg&Data rates may apply.

FIDELITY: Your bank information was updated. If not initiated by your, please call 800-438-2475. Reply STOP to opt out. Msg&Data rates may apply.

She called fidelity and was transferred to their fraud department. They had said this text message is expected and realistic.

I tried googling the number 800-438-2475 but couldn't find too much information on the phone number.

It appears to be a legitimate phone and text message.