1. Apple rewards investors: Shares in Apple jumped as much as 4% in extended trading after the company announced a record cash giveaway to shareholders.

Apple (AAPL) spent $22.8 billion buying back its own stock in the first three months of this year and announced plans for further $100 billion worth of share buybacks.

Apple sold 52.2 million iPhones during the first three months of the year, up just 3% from the same period a year earlier. Analysts had expected sales to hit 53 million iPhones.

WATCH: 'Markets Now' with CNN's Paula Newton and Guggenheim Partners' Scott Minerd at 12:45 p.m. ET

2. Europe health check: The eurozone economy grew 0.4% in the first quarter of 2018 compared to the previous three months, according official data. That's a slowdown from 0.7% in the previous quarter.

The GDP data, which was in line with analyst expectations, could influence plans by the European Central Bank to gradually end its stimulus program. The central bank had recently downplayed some weak regional economic data.

Some European economies are faring better than others: Data released last week showed the UK economy stalled in the first quarter, expanding just 0.1%.

3. Metal moves: Shares in aluminum producer Rusal surged 8% in Hong Kong after the US Treasury extended a deadline for investors to divest their holdings in the sanctioned company.

The Russian oligarch Oleg Deripaska agreed last week to reduce his stake EN+, a company listed in London that is the largest shareholder in Rusal, to below 50%.

Deripaska was hit earlier this month with tough sanctions on Russian oligarchs that target him and his businesses. EN+ and Rusal are part of a tangled web of corporate entities under his control.

Aluminum prices, which spiked dramatically after the sanctions were imposed, have fallen 13% from their recent high.

4. Fed decision: The US Federal Reserve will announce an interest rate decision at 2:00 p.m. ET.

Economists expect the central bank to keep rates on hold, but they will pay close attention to any details that give a sense of the bank's plans.

The Fed signaled in March that the path of future rate hikes could be "slightly steeper" over the next few years than previously thought.

5. Global market overview: US stock futures were mixed.

Major European markets opened higher, while stocks in Asia ended the session mixed.

US crude futures jumped 0.6% ahead of the release of a weekly oil inventories report to trade at $67.70 per barrel.

The S&P 500 closed 0.3% higher on Tuesday and the Nasdaq added 0.9%. The Dow Jones industrial average shed 0.3%.

Before the Bell newsletter: Key market news. In your inbox. Subscribe now!

6. Earnings and economics: CVS Health (CVS), Energizer (ENR), Estee Lauder (EL), Garmin (GRMN), Humana (HUM), MasterCard (MA), Molson Coors Brewing (TAP), and Yum! Brands (YUM) will release earnings before the open.

Avis Budget (CAR), Caesars Entertainment (CZR), Express Scripts (ESRX), Fidelity National (FNF), Fitbit (FIT), Hyatt Hotels (H), Kraft Heinz (KHC), MetLife (MET), Spotify (SPOT), Sprint (S), Square (SQ), Tesla (TSLA), and Valvoline (VVV) will follow after the close.

Gilead Sciences (GILD) slumped 6% in extended trading following a disappointing set of results.

Match Group (MTCH), the owner of Tinder, plunged 22% on Tuesday after Facebook (FB) unveiled a new dating feature.

Markets Now newsletter: Get a global markets snapshot in your inbox every afternoon. Sign up now!

7. Coming this week:

Wednesday — CVS (CVS), Humana (HUM), Kraft Heinz (KHC), Metlife (MET), Molson Coors (TAP), Spotify (SPOT), Tesla (TSLA), Yum (YUMC); Fed meeting

Thursday — Cigna (CI), DowDuPont (DWDP), Kellogg (K), Weight Watchers (WTW) earnings

Friday — Alibaba (BABA), Newell Brands (NWL) earnings; Berkshire Hathaway annual shareholder weekend kicks off; Jobs report