Proshares UltraShort Lehman 20+ Year Treasury Fund (TBT) is rallying and calls are active after Pimco’s Bill Gross said bonds (the dollar and stocks) are under pressure on fears US might lose its AAA credit rating. The comments come the same day S&P downgraded UK’s credit rating. In the options market, volume is picking up in TBT June 52 and 50 calls, as some players brace for additional weakness in bondland. TBT, which moves 2X the inverse of the iShares Long-Term Bond Fund (TLT), is up $1.74 to $51.69 per share.