Some enduring red flags, Filia said, are in the form of politics and geopolitics — growing populism across Europe as well as Middle East and Asian tensions. But more than that he sees shrinking liquidity — central bank spending flows in reverse for the first time in a decade — as the "first real crash test" for momentum and volatility, as well as rising interest rates.
Historic debt levels likely pose another danger, as we're now looking at the largest debt-to-GDP ratios for some of the major G-10 countries in decades. At the same time, we're faced with some of the smallest savings rates across U.S. households in decades and "the worst debt metrics for corporates," Filia said.
Still, Fasanara may be among the more bearish market watchers out there. Strategists at Credit Suisse and LPL Financial, among others, say this bull market has more room to go.
Chief Investment Officer at Hennion & Walsh, Kevin Mahn, told CNBC last month that rather than being driven by central bank accommodation, as before, today's bull market is being carried by stronger fundamentals like economic expansion and earnings. This, he said, would continue to move stocks higher.
But Filia maintains his worrisome outlook — where some experts see promise, he sees pitfalls. And they represent more than one elephant in the room.
"More than a room, financial markets look like a china shop, given their fragility," he said. "There are then several elephants in the china shop."