The Bankrate survey was conducted by Princeton Survey Research Associates International over the telephone in July with 1,002 adults living in the continental U.S. The LendEDU poll was conducted online by OnePoll and surveyed 1,000 American consumers ages 18 and up in late August.
On the digital currency side, a leader at major cryptocurrency investing and trading company Coinbase said investors should still be cautious.
"Everyone should have a bit of exposure to digital currencies because [it] looks like [the] future," said Adam White, head of Coinbase's GDAX exchange. But there's "still a very real chance" some of the digital currencies fall "all the way to zero."
White also said digital currency investors should still heed two investment adages: Never invest in what you don't understand, and never invest more than you can afford to lose.
The cautionary tone echoes what some market watchers have been saying. Elliott Prechter, who writes about the Elliott Wave Theory widely followed by traders, said in July that bitcoin appears to be nearing the fifth and final wave of its latest run higher.
Bitcoin has more than quadrupled in value this year and was trading near $4,718 Monday, according to CoinDesk. Another digital currency, ethereum, has soared more than 3,000 percent to around $300.
The entire universe of cryptocurrencies has multiplied eight times in value this year to $150 billion, according to CoinMarketCap. That's still a tiny fraction of the roughly $200 trillion in gold, cash, stocks and bonds.