* Most net shorts in 10-year T-notes in over a year
* Two-year net longs retreat from highest since April
* Smallest net shorts in 30-year bond futures in two months
Aug 16 Speculators increased their bearish bets on U.S. 10-year Treasury note futures in the latest week amid worries the Federal Reserve might pare its monthly bond purchases, according to Commodity Futures Trading Commission data released on Friday.
The amount of bearish, or short, positions in 10-year Treasury futures held by speculators exceeded bullish - or long - positions by 66,432 contracts on Aug. 13, according to the CFTC's latest Commitments of Traders data.
That was the highest weekly reading of net speculative shorts in 10-year Treasury note futures since late July 2012.
A week ago, speculators held 20,096 net short positions in 10-year T-note futures.
On Friday, worries about less Fed stimulus knocked Treasury futures lower and pushed benchmark 10-year Treasury yields to two-year highs.
Treasury 10-year T-note futures on the Chicago Board of Trade for September delivery closed down 16/32 at 124-31/32, while the yield on cash 10-year Treasury notes rose 6 basis points to 2.825 percent, according to Reuters data.
Speculators also scaled back their bullish bets on two-year Treasury note futures, according to the latest weekly CFTC Commitments of Traders figures.
Speculators' long positions in two-year T-note futures exceeded shorts by 50,518 contracts on Tuesday, down 5,472 from a week earlier, when net longs in two-year T-notes reached their highest level since mid-April.
On the other hand, speculators built up their longs or shrank their short positions in five-year and long-dated Treasury futures in the latest week.
Long trades in five-year Treasury note futures exceeded short positions by 42,408 contracts, or 27,236 more than the previous week.
Last week was the lowest level of net longs in five-year T-notes since mid-January, when speculators had a net short.
Speculators trimmed their net shorts in 30-year bond futures by 3,979 contracts to 1,788 on Tuesday, which was the smallest net short position in two months.
Speculators turned net long in ultra-long T-bond futures earlier this week. Long trades exceeded short ones by 5,026 contracts on Tuesday, compared with a week earlier, when traders had a net short of 10,747 contracts.