10 things you need to know before the opening bell

Here is what you need to know.

Wednesday's the first anniversary of a chaotic day in the markets. The S&P 500 lost 77.7 points, or 3.9%, and China's Shanghai Composite crashed more than 8%, less than a week after the People's Bank of China announced it was devaluing its currency, the yuan. In an afternoon note that day, Brean Capital's Peter Tchir wrote, "I am nervous that in the time it took me to type this the Dow could be plus or minus 200 points since I started."

Germany's economy slowed in the second quarter. Europe's largest economy saw growth slow to 0.4% in the second quarter, down from the 0.7% growth experienced in the first quarter. The euro is down 0.2% at 1.1280.

US crude stocks are piling up. West Texas Intermediate crude oil trades lower by 1.6% at $47.33 a barrel after data released Tuesday by the American Petroleum Institute showed crude stocks unexpectedly rose last week.

The US government is buying 11 million pounds of cheese because no one else will. The US Department of Agriculture is buying $20 million worth of cheese to help alleviate a surplus that is at a 30-year high.

Tesla announced a big upgrade. CEO Elon Musk said Tuesday that the Model S and the Model X would offer batteries that will extend their ranges to 315 miles and 289 miles. Additionally, both models will receive an upgrade to their "Ludicrous Mode."

Pfizer isn't done spending money. On Monday, Pfizer announced it was buying the cancer drugmaker Medivation for $14 billion. Fast forward to Wednesday, and the company announced it's paying AstraZeneca as much as $1.575 billion plus royalties for part of its antibiotics business, The Wall Street Journal reports.

Qantas is awarding 25,000 employees for its record full-year profit. The Australian airline is giving a $3,000 bonus to employees who were included in its 18-month pay freeze after staging one of the greatest turnarounds in Australian corporate history.

Stock markets around the world are mostly higher. Spain's IBEX (+0.6%) leads the gains in Europe after Japan's Nikkei (+0.6%) paced the advance in Asia. Britain's FTSE (-0.2%) and Hong Kong's Hang Seng (-0.8%) are notable laggards. S&P 500 futures are up 1.75 points at 2,187.00.

Earnings reporting remains light. Express reports ahead of the opening bell, while HP Inc. and Williams Sonoma release their quarterly results after markets close.

US economic data flows. FHFA House Price Index crosses the wires at 9 a.m. ET, and existing home sales will be released at 10 a.m. ET. Then, at 10:30 a.m. ET, US crude-oil inventories will be released. The US 10-year yield is up 1 basis point at 1.56%.