Accounting rule makers are considering forcing companies to account for securitized assets, such as mortgage-backed securities, on their balance sheets. A strict reading of that rule force Fannie Mae and Freddie Mac to raise a combined $75 billion in additional capital, according to Lehman Brothers. Fannie Mae shares were rising $2.20 to $17.94 and Freddie was gaining $1.90 to $13.81 in response. GPS-based navigational devices maker Garmin ( GRMN) gained as shares of its rival TomTom fell to a new low. TomTom could have trouble meeting financial requirements for its $4.3 billion purchase of the mapping data supplier TeleAtlas, said a Goldman Sachs analyst. Garmin and TomTom were locked in a fierce battle for TeleAtlas. Shares of Garmin were up $1.55, or 3.6%, to $44.14. Shares of Altair Nanotech ( ALTI) were ticking higher by 33.1% to $1.93 during Tuesday's trading session. The Reno, Nev.-based developer of nanomaterial and titanium dioxide pigment technologies publicized the completion of a demonstration and validation program for a new battery system purchased by AES Corporation ( AES). In a Yahoo! Finance interview, Terry Copeland, the president and CEO of Altair, said that the "positive AES results validate the immense opportunities in the utility sector." Rubicon Minerals ( RBY) rose 13.6% to $1.34 in early trading hours. The Vancouver, Canada-based gold exploration company hit bonanza grade gold in its F2 Zone located in Red Lake, Ontario. In a Rubicon press release, David Adamson, president and CEO said that "it is encouraging to see that the major components documented at the Red Lake Mine are present at the F2 Zone."