CMS Forex - The greenback plunged against most key currencies on Tuesday reversing Monday's gains as the Federal Open Market Committee lowered its target for the federal funds rate 75 basis points to 3.5%. The yen fell against all major currencies as US equity prices stabilized after the Fed's emergency move. US stocks pared their biggest decline since 2002 as the Fed's rate cut helped mitigate concerns of a credit crunch and recession.