Berkshire Hathaway Inc. (BRK-A, BRK-B) held a record $84.8 billion in cash and equivalents at the end of September, the company reported Friday, raising questions about the kind of signal legendary investor Warren Buffett might be sending.

Berkshire's cash pile, which has risen by over 18% since the end of 2015, is now at record levels.

One possible explanation is that Buffett can't find an appealing takeover target. Berkshire's chairman and CEO has said that he prefers to keep a cash cushion of $20 billion, but even subtracting that, the remaining $64.8 billion could buy nearly two-thirds of U.S.-listed public companies outright.

That Buffett is not buying could be a sign that he is not happy with current valuations. Despite suffering the longest losing streak in over 30 years, the S&P 500 is still trading within 5% of the all-time high it hit on August 15. Going by book value, one of Buffett's favorite metrics, the S&P's current multiple of 2.81 is above the historical mean of 2.74, according to multpl.com.

The firm's most recent quarterly report reinforces the impression that Buffett is striking a cautious note. Referencing the conglomerate's insurance business, which accounted for 74% of total revenues in the third quarter, the release states: "We continue to hold significant cash and cash equivalents earning very low yields. We believe that maintaining ample liquidity is paramount and we insist on safety over yield with respect to such balances."

It is possible that Buffett is wary of Tuesday's election like many other investors. "Republican wins White House" topped the list of fund managers' biggest fears in July, August and September, according to a monthly survey by Bank of America Merrill Lynch (it slipped to third place, behind "EU disintegration" and "crash in bond market/rising credit spreads" in October). Buffett has made no secret of his contempt for Donald Trump, publicly calling on the Republican nominee to release his tax returns and blasting him for attacking the Gold Star parents Khizr and Ghazala Khan. Buffett has also endorsed Hillary Clinton and lent his name to the Buffett Rule she advocates, which would tax those making more than $1 million per year at least 30%. Another possible explanation for Berkshire's record cash pile is that it is gearing up for another big acquisition. The Omaha World-Herald, writing ahead of Berkshire's earnings release last week, rattled off a few possible targets: Norfolk Southern Corp. (NSC), Dr Pepper Snapple Group Inc. (DPS), Kroger Co. (KR), Dollar Tree Inc. (DLTR), Principal Financial Group Inc. (PFG) and Phillips 66 (PSX) (in which Berkshire already holds a 10.5% stake), Estee Lauder Companies Inc. (EL), Weyerhaeuser Co. (WY) and AutoZone Inc. (AZO) - or a combination. As it would turn out, Berkshire's pockets are around $10 billion deeper than the $75 billion in cash the World-Herald projected.

Berkshire could also buy back its own stock, Edward Jones analyst Jim Shanahan told Bloomberg Friday, adding that the stock "seems really cheap to me." Perhaps one of the more attractive investments available to Berkshire at the moment is Berkshire itself.