According to the latest breakdown of short positions by Deutsche Bank, speculators increased their net shorts by $7.7 billion in 10Y cash equivalents to $99.4 billion, a third successive week of record low positions.
The above charts and comments from ZeroHedge via Deutsche Bank.
For every future short there is a future long, so the net is always zero. In this case, the commercial traders are long and the speculators are short.
Eurodollars have nothing to do with euros. They are actually an interest rate play on US dollars. Short eurodollars is a bet that interest rates in US dollars will rise.