Stock losses grew heavier as the afternoon wore on with a selloff in crude oil and health care stocks leading Wall Street into the red. Crude settled at a one-week low after a weekly reading on U.S. oil inventories showed a build.

U.S. stocks moved higher in quiet trading Wednesday as investors look ahead to a closely-watched speech by Federal Reserve Chair Janet Yellen on Friday.

U.S. stocks shrugged off a decline in oil prices Tuesday, starting the trading session higher amid better-than-expected results from Best Buy .

Earlier momentum deflated by the end of the day, though Wall Street did manage to close with slight gains. Crude oil supported stocks thanks to a surprise rally driven by speculation Iran may participate in a production freeze. Tesla gave back most of the day's gains after announcing new versions of its Model S and Model X vehicles, including new batteries for faster performance. Expectations had been high after CEO Elon Musk made mention of an announcement earlier in the day.

Wall Street will get more clues as to the Federal Reserve's rate-hike plans at the end of the week, but uncertainty over what they might be led to jittery trading on Monday. Crude was also a drag, snapping a seven-session winning streak.

U.S. stocks moved lower Monday as oil prices dipped back below $50 a barrel. The declines came amid fears of more supply from producers in Iraq, Nigeria and Iran. Oil prices are up

Stocks were mixed on more speculation over the Federal Reserve's rate hike timeline. Crude prices were also in flux, though likely to score a weekly gain of around 7%.

Stocks pared losses heading into market close as crude ended its seventh session of gains. The Nasdaq hugged the flatline, while the S&P 500

Brent Crude oil hit $50 a barrel overnight. It was just 2 weeks ago that the price was threatening to go under $40 a barrel. Oil has gained more than 20% over that time. There's continued optimism that OPEC will cap production at its meeting next month. Uber has been very successful at disruption the on-demand ride business but it will have to start turning some very large profits to justify the $68 billion valuation given to it by investors. An New York University Professor ran available numbers on the San Francisco based company and came up with a value of just $30 billion. U.S. Olympic swimmer Jimmy Feigen has reached an agreement with officials in Rio De Janeiro to make an $11,000 donation to a Brazilian charity in an effort to resolve a dispute over a claim of robbery, according to media report. Brazilian authorities accused Feigen, Ryan Lochte, Gunnar Bentz and Jack Conger of making up a story about a robbery to cover up their acts of drunken vandalism.

U.S. stocks moved lower Friday as oil prices lost steam after a week-long rally. Oil rose $4 this week and trades just over $48 a barrel. 'Oil doesn't have to go meaningfully higher, but we can't support a bull market in stocks or anything without oil at least stabilizing,' said David Nelson, chief strategist at Belpointe Asset Management. Viacom's board has reached an agreement on the ouster of CEO Philippe Dauman, sources tell TheStreet. He is expected to score a severance package worth $72 million. COO Tom Dooley is expected to be take the role as interim CEO. Shares gained 2.1 percent. Foot Locker posted second quarter earnings of $0.94 a share, beating estimates by $0.04. Revenue rose 5 percent year-over-year to $1.78 billion, slightly ahead of the $1.76 billion analysts had expected. Same store sales rose 4.7 percent. The stock is up 5 percent. Estee Lauder reported earnings of $0.43 a share, beating estimates of $0.40. Sales gained 5 percent year-over-year to $2.65 billion, largely in-line with estimates. Shares slipped almost 4 percent. TheStreet's Scott Gamm reports from Wall Street.