Janus Capital has rallied its sales force around Bill Gross, helping to push the assets in his new mutual fund past the $1 billion mark in November.

Gross's strong performance also contributed to the fund's increased assets as bets on derivatives linked to China and Mexico appear to have paid off, analysts say. The Janus Global Unconstrained Bond fund returned 0.36% during the month, beating out 82% of similar mutual funds, according to fund research firm Morningstar.