From http://w1mx.mit.edu/flea-at-mit/
As MIT has announced that only seniors will be back on-campus with heavy restrictions in place, we have determined that we won’t be able to hold Swapfest without excessive risk for the rest of the calendar year. Swapfest will (tentatively) pick back up on April 18 of next year, and anyone who submitted preregistration should have either recently received an email or will shortly receive postal mail returning their payment.