10 things you need to know before the opening bell

Burhan Ozbilici/AP

Turkey's Interior Minister Suleyman Soylu, rear-left, follows President Recep Tayyip Erdogan, center.

Here is what you need to know.

The Turkish lira continues its plunge. It hit an all-time low against the dollar on Friday after a Turkish delegation in Washington failed to prevent US sanctions over the arrest of the American pastor Andrew Brunson. The European Central Bank said it was concerned about lenders' exposure to Turkey.

The pound is still falling, too. It hit a fresh 11-month low against the dollar after data from the UK Office for National Statistics showed faster second-quarter gross domestic product, but a manufacturing recession.

Russia says US sanctions on banks or foreign currency dealings would be a declaration of "economic war." The US on Wednesday announced a new round of sanctions targeting Russia that pushed the ruble to two-year lows

Dropbox beat on second-quarter earnings and announced a key executive was stepping down. Chief Operating Officer Dennis Woodside, long considered a key lieutenant to CEO Drew Houston, is leaving the company.

Tesla's board may reportedly tell Elon Musk to recuse himself from talks about taking the company private. The board has told Musk he must consult different advisors as they seek counsel, CNBC reported.

Tesla is now worth less than it was before Elon Musk's $420 tweet. The stock closed down 5% Thursday at $352.45; it was worth $358 when Musk tweeted Tuesday about taking the company private.

Bank of America asked 65 investors their biggest fear - and the top response shows just how vulnerable markets are right now. A sharp loss of liquidity is now their biggest worry.

Samsung unveils its Galaxy Note 9 and answers to the Apple Watch and HomePod. The company announced a slew of new products at an event in Brooklyn, New York on Thursday.

Inflation numbers are on deck. The July consumer-price index will be released at 8:30 a.m. ET.

Global equity markets are in the red. Dow futures are down 0.4%, or 106 points. The 10-year yield is down four basis points at 2.895%.