Quote from RoughTrader:
No, not that I have seen. I see the bid and the ask track each other quite tightly even during news events. The most I've seen the bid and ask spread at is 3 ticks. Most of the time, you can get in and out with limit orders and don't have to pay any spread, just commish.
RoughTrader
But can you get in with stop orders in the increasingly popular "news straddle" style? I bet you'd see massive slippage if you tried that at 0829 EST on NFP Friday.