The home invasion robbery was reported at 1:05 a.m. in the first block of Waverly Place.
The suspect, a man believed to be between 30 and 40 years old, entered the home, grabbed two kitchen knives and threatened the victims, two women ages 65 and 86, according to police.
The suspect then took the victim's property, including a debit card and cellphone, then fled. He had not been found as of this morning, police said.
The women were not injured in the robbery.
Anyone with information about the case is asked to call the Police Department's anonymous tip line at (415) 575-4444 or to send a tip by text message to TIP411 with "SFPD" in the message.