In light of the Easter Holiday and subsequent market closures in both London and Europe, Treasury trading was light and lacking in liquidity. Prices opened under pressure, a follow-through from the selloff in Tokyo as the "safe-haven" terror related trade began to unravel.
In addition, hawkish comments by Fed Parry (though not a voting member and about to retire, with Janet Yellen taking his place), regarding rates: He said the fed funds rate should be at 3.5%. His comments further pressured Treasuries.
Flows were light, but biased towards the sellside from speculatives and dealers. Option flows were mixed, with call buying by a mortgage servicer by mid-morning, stemming some of the losses. But past noon, retail liquidations of 5-year and 10-year notes pulled prices lower. But the magic 4.25% held again, so some speculative short covering helped prices recover, though only barely.