If it was 1hr after the individual buy, it shouldn't synchronize sales. The buys are at different times, so the sales will be too. If you really want to stop HFT (which on the evidence available is actually nothing to do will the current market woes) you could simply make order cancellations more expensive, this would stop them all in their tracks. Maybe, but it might be difficult to make them expensive enough that it had an effect without other unintended consequences. Still seems like a political decision to me, the whole reason for the crises lunching from drama to drama is the refusal to let the euro die. But of course politicians would rather do any amount of damage than see their power bases eroded. And yet, saving the Euro (by centralizing the EU fiscal policy) would be a big erosion of power for member-state politicians. I think they are just not willing to face what it will mean for the EU, even as it looks more and more inevitable.