Magoon wasn't alone in his concern.
"Does the lack of fear reflect an exhausted, tired market that believes zero volatility is normal, or is it an example of enormous complacency?" Bill Blain, a strategist at Mint Partners in London, asked in a note to clients, Bloomberg reported.
Also warning against complacency, on the timing of interest rate increases by the Federal Open Market Committee, was Federal Reserve Bank of Cleveland President Loretta Mester.
"It's important for the FOMC to remain very vigilant against falling behind as we continue to make progress on our goals," Mester said in a speech on Monday in Chicago.
"If we delay too long in taking the next normalisation step and then find ourselves in a situation where the labour market becomes unsustainably tight, price pressures become excessive and we have to move rates up steeply, we could risk a recession," Mester warned.
In the Dow, declines in shares of Chevron and those of Cisco, down 1.6 per cent and 1.1 per cent respectively, outweighed advances in shares of Nike and those of Wal-Mart, recently both up 1 per cent.
Energy stocks fell with the price of oil. In its monthly Short-Term Energy Outlook, the US Energy Information Administration forecast domestic output will rise to a record 9.96 million barrels a day in 2018, up from last month's forecast for 9.9 million barrels.
Meanwhile, shares of Valeant Pharmaceuticals soared, trading 23.3 per cent higher as of 2.47pm in New York, after the company posted its first profit in six quarters and upgraded its full-year earnings outlook.
"Our first quarter performance demonstrates that we are delivering on our commitments," Joseph Papa, Valeant's chief executive officer, said in a statement. "We met our internal expectations, and we are continuing to make progress on our key initiatives, focus on the turnaround of our core businesses and improve internal operating efficiencies."
Not all analysts are convinced the company has turned its business around.
"In reality, Valeant's sales are declining, its leverage ratio has increased, and we think its pipeline is weak," Wells Fargo analyst David Maris said in a note, rating the stock a sell, according to Bloomberg.
In Europe the Stoxx 600 Index ended the day with a 0.5 per cent gain from the previous close. France's CAC40 Index added 0.3 per cent, Germany's DAX Index rose 0.4 per cent, while the UK's FTSE 100 Index increased 0.6 per cent.
The global earnings recovery looks "impressive," BlackRock chief investment strategist Richard Turnill wrote in a note, Bloomberg reported. He forecast more upside in European equities than in their US peers, and recommends diversifying geographically in equity portfolios.
