7.8% of my Asset Allocation is in cash. My plan calls for 5% in cash or bonds so I'm a little high right now, though I have no bonds. One culprit is that our 2014 IRA contributions are building up in a checking account while I try to decide whether to go traditional or Roth this year. A sudden market drop would certainly get me off the fence on when to deploy this cash. The other issue is my HSA account. The investment fees are kind of high so I've just left it in cash so far, but as it nears $10k, the fees drop below 1% which is sorta good enough (though if I had ignored this fee issue, I would have gained much over the past 2 years. doh).
I'm willing to send all the cash in my AA to stocks in a market decline to go 100% stock, and the only reason I have the 5% designated as part of my AA is so that I can take advantage of rebalancing opportunities.
My EF is not considered in the above because it's not a rebalancing candidate, though I have reduced it and invested some of it in taxable since becoming a MMM reader. It's now only about $10k.