Updated from 6:59 a.m.
NEW YORK (TheStreet) -- Here are 10 things you should know for Friday, May 1:
European stocks were quiet Friday. Continental European markets are closed for the May Day holiday, and London stocks were little changed. Mining stocks were among the strongest performers.
2. -- The economic calendar in the U.S. on Friday includes the Markit PMI manufacturing flash index at 9:45 a.m., the ISM manufacturing index at 10 a.m., the University of Michigan's consumer sentiment index at 10 a.m., and construction spending numbers at 10 a.m. Motor vehicle sales data also comes in Friday.
3. -- U.S. stocks on Thursday declined markedly as investors thought over weak economic growth numbers and a large influx of earnings reports.
4. -- Tesla (TSLA) will expand from manufacturing electric cars to working more on batteries for home and business use, CEO Elon Musk said. The new systems will be called the Powerwall Home Battery and the Powerpack, which is more business-oriented. The systems will use technology derived from Tesla's electric cars. The batteries are designed to work in conjunction with solar power; users can gather energy during the day and continue to operate off of it at night via the batteries.
Musk also is chairman of Solar City (SCTY), a solar-panel manufacturer and seller that was founded and run by his cousins.
In premarket trading, Tesla stock was up 1.2%.
5. -- Warren Buffett's Berkshire Hathaway (BRK.A) (BRK.B) reports earnings Friday. Berkshire Hathaway is hosting about 40,000 investors this weekend at its annual meeting in Omaha. What's been called "Woodstock for Capitalists" kicks off Saturday morning. There has been much speculation over who will succeed Buffett at the head of Berkshire Hathaway -- he is 84 and has been running the company for 50 years.
Berkshire Hathaway's class B shares were rising by 0.07% in premarket trading.
6. -- The CME (CME) -- parent company of the Chicago Mercantile Exchange, the Chicago Board of Trade and other trading exchanges -- has suspended two gold traders for "spoofing," or placing and then canceling orders. The technique is also what U.K. CME trader Navinder Sarao used when he allegedly triggered the "Flash Crash" of May 6, 2010. The Flash Crash temporarily erased about a trillion dollars worth of value from the Dow when orders intended to be canceled instead deflated the index by 9%.
When traders spoof orders, they place orders they don't intend to fill. Instead, the orders can help them push prices down or draw out other buyers. Then the traders place their real orders, often in multiple separate units.
The suspended traders, Heet Khara and Nasim Salim, both trade CME gold and silver futures the Comex exchange in New York. They are now barred from trading for 60 days, the exchange said in a disciplinary statement.
CME's stock was up 0.1% in premarket trading.
7. -- Mortgage lenders Fannie Mae (FNMA) and Freddie Mac (FMCC) didn't look very good in a "stress test." The companies required taxpayer bailouts of $187 billion during the 2008 financial crisis. But they might still require outside support of $157.3 billion in case of a major recession, regulators said.
The companies have repaid their loans from the financial crisis, but the stress test will push the companies to shore up their balance sheets.
Together Fannie Mae and Freddie Mac own or guarantee $5 trillion in U.S. mortgages -- about 50% of the mortgage market.
8. -- Employment-focused social network LinkedIn (LNKD) set low guidance for the second quarter and for the full year. The company announced earnings Thursday after the closing market bell. It said it expected second-quarter adjusted profit of 28 cents a share, far lower than the average analyst forecast of 74 cents. Although LinkedIn did beat first-quarter analyst estimates, it wasn't enough to satisfy shareholders.
LinkedIn stock was plummeting by 20% in premarket trading. LinkedIn shares had risen 59.3% in the past 12 months.
9. -- May has arrived, and the old market adage to "sell in May and go away" has popped up again. The strategy is designed to avoid summer trading, which has lower volume. The technique still has a few adherents.