The majority of investment professionals I follow right now are all cash-heavy. The general consensus seems to be that we're either just before or smack dab in the middle of the euphoria phase of stock market lifecycles:

With pullback being estimated between 30% (Rosenberg) and 70% (Blumenthal) expected between Q1 2018 and Q3 2018. Those that have to find somewhere to dump an investment are being encouraged to buy commodities, France or Japan. I'm mostly cash right now but I've done okay with a France ETF that doesn't make me sad. I also dumped some cash into Alaska Airlines last week because they've basically beaten Delta for the West Coast and they're expanding into new airports (and they missed earnings by a few pennies so the market punished them by dropping them from a 52-week high to a 52-week low).

I've said it before. I like TD Ameritrade because it's easy to deal with and they give you the play money account which tends to curb my stupidest instincts.

EDITED TO ADD: interest rates right now are punishing savers. They were specifically chosen to keep money from being placed in cold storage and to encourage investment. Expect the Fed to attempt to remedy this so they have some gas, but expect them to overcompensate because their models are dependent on the Philips Curve and because, frankly, recessions do have to happen at some point. With Yellen out, and William Dudley (NY Fed) walking away, that isn't iron-clad but the guys that have been forestalling a depression by fucking over retirees are about to be out.