Donald Trump last week discussed his medical history on "Dr. Oz," duped the media into broadcasting an endorsement event, and made dubious and conflicting claims about his tax plan. The stocks that could do well under his presidency made similarly odd moves.

The Republican presidential nominee, seeing tightening polls, in recent days appears to have pivoted away from the toned-down, more serious turn his bid has taken and back towards the original, off-the-cuff Trump.

In an interview with The Washington Post Wednesday, Trump touted his poll numbers and said that while he had been respectful during rival Hillary Clinton's bout with pneumonia, "that doesn't mean I'm going to stay there." During the same interview, he refused to comment on whether he now believes President Barack Obama was born in the United States. Two days later on Friday, he said that he now believes Obama was born in the U.S. at a highly-anticipated press conference at his new hotel in Washington, D.C. At the same event, he falsely claimed Clinton began the "birtherism" movement and that he brought it to an end in 2011 (he championed the theory for years).

Later in the day Friday, Trump suggested at a rally in Florida that the Secret Service protecting Clinton should disarm and "see what happens to her." And on Twitter, he attacked New York Times writer Maureen Dowd and former Defense Secretary Robert Gates over the weekend.

Wacky @NYTimesDowd, who hardly knows me, makes up things that I never said for her boring interviews and column. A neurotic dope!

— Donald J. Trump (@realDonaldTrump) September 17, 2016

Crazy Maureen Dowd, the wacky columnist for the failing @nytimes, pretends she knows me well--wrong!

— Donald J. Trump (@realDonaldTrump) September 17, 2016

Never met but never liked dopey Robert Gates. Look at the mess the U.S. is in. Always speaks badly of his many bosses, including Obama.

— Donald J. Trump (@realDonaldTrump) September 17, 2016

TheStreet's Donald Trump Stock Portfolio, a set of 15 stocks we have identified that could do well under a Trump presidency, declined 1.68% last week from market close Friday, September 9 to market close Friday, September 16. The Clinton portfolio fell by 0.38% during the same period.

Since we began tracking them in late July, the Trump portfolio has declined by 8.53%, and the Clinton portfolio has fallen by 6.09%.

The Geo Group (GEO - Get Report) was the top performer in the Trump portfolio last week. Its shares climbed 7.97% to $23.17. A Times report Friday that a criminal justice overhaul bill that would have reduced federal mandatory sentences was dead in the Senate gave the private prison operator a bump. Geo and fellow private prison company Corrections Corp. of America (CXW - Get Report) plunged last month on news that the Justice Department planned to phase out federal contracts with such firms.

Microsoft (MSFT - Get Report) , Northrup Grumman (NOC) and Tetra Tech (TTEK - Get Report) were the only other Trump portfolios to end last week in the green, up 1.85%, 0.84% and 0.66%, respectively.

U.S. Steel (X - Get Report) , the only stock that overlaps with the Clinton portfolio, was the biggest loser in the Trump portfolio last week. Its shares fell 6.48% to $15.91. The U.S. International Trade Commission last week affirmed anti-dumping and anti-subsidy duties on hot-rolled flat steel imports from seven countries, and the U.S. Commerce Department levied anti-dumping and anti-subsidy duties on certain Chinese products -- both of which should have been good news for U.S. Steel, the stock price of which dropped anyway. Shares of the company are down more than 25% over the past month, but on Monday, KeyBanc Capital Markets raised its rating on the stock.

Cemex (CX - Get Report) shares dipped 6.54% to $7.29. At the start of the week, the Monterrey, Mexico-based company announced that one of its U.S. subsidiaries had agreed to sign its Fairborn, Ohio cement plant and terminal in Columbus, Ohio for $400 million.

Two weeks ago, the Bitcoin Investment Trust (GBTC) was the top gainer in the Trump portfolio, climbing nearly 15%. Last week, however, it declined again, falling 5.42% to $87.02. The price of Bitcoin itself is up about 40% year-to-date.

Here's how the entire Trump portfolio did last week, leading with the top gainers:

The Geo Group 7.97%

Microsoft 1.85%

Northrup Grumman 0.84%

Tetra Tech 0.66%

Lockheed Martin (LMT - Get Report) -0.21%

Randgold Resources  (GOLD - Get Report) -1.29%

Boeing (BA - Get Report) -1.42%

Capital One Financial (COF - Get Report) -2.01T

Steel Dynamics (STLD - Get Report) -2.13%

Oracle (ORCL - Get Report) -2.77%

ExxonMobil (XOM - Get Report) -3.24%

Elbit Systems (ESLT - Get Report) -4.86%

Bitcoin Investment Trust -5.42%

Cemex -6.54%

U.S. Steel -6.58%