NEW YORK (TheStreet) -- The economy has been one of the major concerns over the past five years, Joseph Terranova, chief market strategist for Virtus Investment Partners, said on Wednesday's CNBC "Fast Money Halftime Report." As long as the economy continues to improve, stocks can continue to rally. 

U.S. corporate tax rates are likely going to be a discussion over the next several months now that Republicans have reclaimed the Senate, said Pete Najarian, co-founder of and If there is tax reform, that could give a big boost to technology and pharmaceutical companies. 

With the changes in Congress, it's likely the Keystone pipeline will become a priority in the not-so-distant future, according to Jon Najarian, co-founder of and Pipeline and medical device stocks should do well going forward. 

While the U.S. stock market could be setting up for a "Goldilocks scenario," investors should be cognizant of the slowdown in China and Europe, warned Stephen Weiss, founder and managing partner of Short Hills Capital Partners. Retail and health care stocks should do well. 

West Texas Intermediate climbed $1.25 to $78.42 per barrel. John Dowd, a portfolio manager at Fidelity, said the decline in oil prices has put pressure on energy stocks, creating some good buying opportunities. He likes EOG Resources (EOG - Get Report) and Anadarko Petroleum (APC)  but warned that many integrated oil stocks will be unlikely to cover both capital expenditures and their dividends. 

Gold has also been hit hard in recent trading and is down roughly 2% to $1,145 per ounce on Wednesday. The yellow metal could "flush" down to $1,050 or even $1,000 per ounce, Jon Najarian said. If it does, then it's a buying opportunity. 

If investors like gold, they should like silver even more, Terranova reasoned. The metal has been hit harder than gold this year and has industrial uses as well. 

While the two traders seemed to agree that gold is a buy at some point, one thing they didn't agree on was Amazon (AMZN - Get Report) . Terranova said the Street is going to continue "punishing" the stock for not being able to grow profits and margins. He is not a buyer. 

Jon Najarian disagreed, arguing the stock has quickly rebounded from the lows of its recent decline and is likely to rally into Black Friday.

Peter Thiel, co-founder of PayPal, didn't seem to care about the short-term fluctuations in Amazon's stock price. "It's a super-hard company to evaluate," he said. But betting against CEO Jeff Bezos over the long term isn't a very good idea. Wall Street focuses too much on short-term profitability and not enough on the long-term potential, Thiel said. 

Investors should wait for the stock to move higher into Black Friday and use that rally as a selling opportunity, Weiss said about Amazon. 

Speaking of tech valuations, New York University's Professor of Finance, Aswath Damodaran, argued that shares of Twitter (TWTR - Get Report) and GoPro (GPRO - Get Report) appear overvalued. GoPro makes cameras, but is valued like a social media stock, he said. Even if the company does grow into a media company, how will it make money? 

After five quarters now, Twitter still hasn't found a way to become more profitable. Management needs to improve its execution like Facebook's (FB - Get Report) management did, Damodaran explained, otherwise the stock is going to head lower. He is not a short-seller of either stock.

Weiss agreed with Damodaran about both stocks, but Najarian disagreed on GoPro. He acknowledged the valuation was high, but argued that the company still has a lot of future growth ahead of it, especially internationally. 

For their final trades, Jon Najarian is buying Canadian Natural Resources (CNQ - Get Report) , Weiss said to buy Tenet Healthcare (THC - Get Report) and Pete Najarian is buying Morgan Stanley (MS - Get Report) . 

-- Written by Bret Kenwell 

Follow @BretKenwell