Here are the most important news, trends and analysis that investors need to start their trading day:

• Dow set to drop as it tries to hold its weekly turnaround
• Bitcoin sinks as China intensifies crackdown on cryptocurrencies
• Bond yields rise as China Evergrande contagion fears fade
• CDC chief overrules panel, clears Pfizer boosters for front-line workers
• Costco brings purchase limits back on toilet paper, other items

1. Dow set to drop as it tries to hold its weekly turnaround

U.S. stock futures dropped Friday, one day after another strong rally pushed the Dow Jones Industrial Average, the S&P 500 and the Nasdaq into positive territory for the week. This year, the historically troublesome month has been quite volatile.

The Dow's 506 point surge Thursday and Wednesday's 338 point jump more than made up for Tuesday's slight drop and Monday's 614 point plunge. The S&P 500 also saw back-to-back gains. The Nasdaq advanced for three straight sessions. All three stock benchmarks, while still down for the month, were roughly 2% shy of their most recent record closes.

Shares of Dow stock Nike dropped 5% in Friday's premarket, the morning after the company said global supply chain congestion is hurting the business more than it anticipated. The sneaker giant lowered its fiscal 2022 outlook. Nike did beat estimates on earnings but missed on revenue.

2. Bitcoin sinks as China intensifies crackdown on cryptocurrencies

Bitcoin plunged Friday, with traders rattled by tough talk out of China on cryptocurrencies. In a Q&A posted to its website, the People's Bank of China said services offering trading, order matching, token issuance and derivatives for virtual currencies are strictly prohibited. Overseas crypto exchanges providing services in mainland China are also illegal, China's central bank said. Bitcoin fell 7% to under $42,000. It hit an all-time high over $64,000 in April, but sold off in June and July, even dipping briefly below $30,000. Since mid-July, bitcoin had been gaining ground, making a recent top around $52,000 earlier this month.

3. Bond yields rise as China Evergrande contagion fears fade

The U.S. 10-year Treasury yield rose to more than 1.42% on Friday, back to highs seen in July. The yield, which moves in the opposite direction to price, declined earlier this week when investors sought safety and bought bonds as the deteriorating China Evergrande Group situation slammed stocks Monday. However, as worries faded about the risk of financial contagion if the Chinese property giant were to collapse, U.S. Treasury prices dropped and yields rose. Evergrande has not said whether it will make an $83 million payment on a U.S. dollar denominated bond that was due Thursday. The embattled Chinese developer made a payment on a local bond Wednesday.

4. CDC chief overrules panel, clears Pfizer boosters for front-line workers

The head of the Centers for Disease Control and Prevention overruled an advisory panel Friday, approving the distribution of Pfizer's Covid boosters to a wide array of workers across the U.S. CDC Director Dr. Rochelle Walensky signed off on a series of recommendations from the panel, including distributing the shots to older Americans and adults with underlying medical conditions at least six months after their second shots. But in an usual move, she broke from the panel by also clearing boosters for those in high-risk occupational and institutional settings.

5. Costco brings purchase limits back on toilet paper, other items

Costco's chief financial officer said the company is putting some purchase limitations back on key items, including toilet paper, paper towels, bottled water and high-demand cleaning products. During Costco's post-earnings call Thursday, CFO Richard Galant said the limits are being imposed for a different reason than earlier in the pandemic. "A year ago there was a shortage of merchandise" he said. "Now they've got plenty of merchandise but there's two- or three-week delays on getting it delivered." Costco beat estimates with its latest quarterly earnings.

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Correction: This version corrects that the Dow, S&P 500 and Nasdaq were positive for the week, as of Thursday's close, not for the month.