Even before Trump, US exporters complained that the dollar was too strong

The dollar has been rising steadily since Americans elected Donald Trump as president. That's bad news for companies that sell goods and services abroad, and some investors are ready to blame Trump for weak earnings due to the strong dollar.

But companies were already complaining about the strong dollar long before Trump was on deck for the Oval Office. There were plenty of instances of companies pointing to currency issues as an explanation for low earnings earlier this year.

Some of the big names that noted currency headwinds were Whirlpool, Kraft Heinz, Apple, Procter & Gamble and Alexion Pharmaceuticals. A strong greenback makes it more expensive for buyers in foreign countries, who are usually spending their own currency, to buy U.S.-made goods that are priced in dollars.

Research from Pavilion Global Markets from early in the third-quarter earnings season showed that the strong dollar was the top reason cited by companies for bad earnings — more than wages, oil prices, the election, Brexit, the Federal Reserve or China. That data came out four weeks before the election.

Some companies have managed to adjust to the dollar's strength. Caterpillar's third-quarter results showed the company making a net profit from the impact of currency translation and hedging, versus a loss in the same period a year earlier.

And not everyone thinks the dollar will continue to rise. Jim Paulsen from Wells Capital Management told CNBC on Monday that he thinks the dollar is going down next year, mainly due to rising inflation expectations.