If your account holds Retirement Mortgage (TRM) interval funds (such as TAKNX, CELFX, or CRDIX), those normally sell only once a quarter on set dates. When you wish to withdraw money from your account or initiate a rollover, we buy those holdings from you between those dates (so you do not have to wait for the interval fund liquidation date), and the 'Interim Liquidity Form' is the agreement for that buyout. This is why a TRM withdrawal takes longer, about 15 to 20 business days (or 3 to 4 weeks).