The product pushers on Wall Street love having a catchy phrase that helps them sell anything hot in the market, and right now that phrase is “Trump stocks.”  This loosely defined group of companies supposedly will benefit from the president’s plans to expand the economy, and yes, a new set of winners and losers will emerge as the new administration shifts direction away from the Obama years. But investors should be wary because the stock market’s easiest explanations often provide the hardest lessons.

It wasn’t long ago that investors embraced the BRIC countries—Brazil, Russia, India, and China—as the logical winners of the world’s huge appetite for energy and the need to produce more of it. That theory worked well until Saudi Arabia undermined the pricing power of the OPEC cartel. Saudi Arabia’s single-minded determination to drive down oil prices sent energy stocks reeling.

And we all remember the infamous “dot bomb” collapse 16 years ago when dozens of Internet stocks imploded. These companies were thought to be immune from the traditional ways of determining a stock’s value, like profitability, until it turned out that making money mattered after all. As both investors and newspapers soon discovered, the traffic on a company’s website was no guarantee of a robust revenue stream.

No Pure Plays

That’s why you should avoid jumping blindly into any company branded as a Trump stock, and as you might expect, the traditional GOP stronghold of defense companies leads this coterie of stocks. From Nov. 8 until the end of February, the SPDR S&P Aerospace & Defense exchange-traded fund gained 18%, nearly double the return of the S&P 500 index.

Excitement also has been building over the infrastructure companies that are most likely to benefit from Trump’s plan to rebuild the country’s roads, bridges, and airports. That plan, however, is short on details and has been placed on the back burner until 2018 to make room for higher priorities this year. The uncertainty over when Congress might pass an infrastructure bill can be seen in the performance of the PowerShares Dynamic Building & Construction ETF. It jumped 20% the month following Trump’s victory but has vacillated sideways ever since.

That’s because other than some key winners from defense spending, there really aren’t any “pure plays” in a Trump presidency, so you should resist characterizing an entire sector as one solely made up of Trump stocks. For that matter, you also shouldn’t rule out all companies in a sector that Trump’s agenda either ignores or harms.

Win With the Losers

When Trump proposed increasing the military budget, he also suggested cutting spending for education, science, welfare and the environment. But Americans will still get an education, scientific research will continue, the poor will need assistance and no one will want to drink dirty water. Trump might push these items off the federal ledger, but they’re not going away, although weaker businesses in those fields may eventually fund had. This form of Darwinism typically happens at the margins and has the effect of concentrating more capital in the stronger companies that survive. As a result, they can turn out to be excellent investments even though they were never Trump stocks.

Caught in the middle are sectors like healthcare, which is waiting for a viable alternative to the Affordable Care Act. The Republican proposal currently on the table has already been criticized as “Obamacare Lite” and may lack the votes needed to pass. Meanwhile, the iShares US Healthcare ETF has mostly bounced around in response to Trump’s conflicting comments about healthcare. During the first week of November, the ETF jumped 8% thanks to Trump’s victory; one month later the fund  had dropped more than 4% before gaining it all back in January. In February the ETF rose 6% as Trump signaled he preferred to revise, but not entirely replace, the ACA.

After recalibrating share prices based on the president’s agenda, the market now needs to winnow down the winners and losers. The effect this exercise will have on the overall market may be neutral or even slightly negative, depending on how well legislators can transform Trump’s words into actions. Making the legislative sausage is bound to get messy, but by the time Congress finishes, we should have a much clearer idea of what a Trump stock really is and what it isn’t.