September was a pretty good month for stocks in 2018. 

Not so much in 2019, says one trading expert. 

"I would say it's going to be flat to slightly up from where we're finishing in August," said Shawn Cruz, trading strategy manager at TD Ameritrade. "That's going to really be dependent on what we get on the trade front." 

The reason it's trade Cruz is watching is because, "I think an accommodative Fed is already more or less priced in, so that's not really, to me, going to be a big catalyst for movement in the S&P." When put against Cruz's belief that there won't be much progress on trade, it's hard to see upside in stocks. 

The S&P 500 is up 16.5% year-to-date, with the average forward one-year earnings multiple near 17, higher than the 10-year average of 14.8. Semiconductor stocks, which have accounted for a solid amount of stock market performance in 2019 are looking riskier with potentially higher tariffs on consumer electronics goods, as UBS chief investment officer of wealth management Mark Haefele pointed out in a note this week. Their shares PHLX Semiconductor ETF (SOXX - Get Report) is up 31% year-to-date. 

Still, the FAANG group, which has also enjoyed strong performance in 2019, could potentially continue to gain. Earnings multiples in the group are historically low. Facebook (FB - Get Report) trades at 19 times next year's earnings, and has a growing Instagram platform to lean on. Apple (AAPL - Get Report) trades at 16 time earnings and has a burgeoning services business to lean on. 

But as for the rest of 2019, "I don't think any sort of a strong rally is going to be in place." 

Facebook and Apple are holdings in Jim Cramer's Action Alerts PLUS Charitable Trust Portfolio. Want to be alerted before Cramer buys or these? Learn more now. 

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