Stocks: 5 things to know before the open

Click chart for in-depth premarket data. LONDON (CNNMoney) Quarterly earnings continue to come in thick and fast on Wall Street, but that's not the only thing happening Tuesday.

Here are the five things you need to know before the opening bell rings in New York:

1. U.S. earnings: Major companies including UPS (UPS), Reynolds American (RAI) and Pfizer (PFE) are slated to report earnings before the opening bell.

Twitter (TWTR, Tech30), American Express (AXP) and Sturm Ruger (RGR) will report after the close.

Shares in Herbalife (HLF) are declining by more than 10% premarket after the company posted earnings that missed analysts' forecasts.

2. European earnings: Shares in two major European banks -- UBS (UBS) and Deutsche Bank (DB) -- were under pressure after both reported earnings and flagged new litigation risks.

Shares in BP (BP) were down 1% after the oil giant reported its latest set of results. BP, which owns a big stake in Russian oil giant Rosneft, has warned that it could suffer if Western nations slap more sanctions on Russia over the crisis in Ukraine.

3. More sanctions coming? European officials continue to work Tuesday on details of new sanctions that could restrict Russia's access to European financial markets, arms and energy technology. Western nations have upped their pressure on Russia since flight MH17 was brought down in the region.

Japan introduced its own sanctions on Russia, largely reflecting previous measures adopted by the EU.

Russia's main Micex index was dipping into the red, alongside most of Europe's major stock markets.

U.S. stock futures were also in negative territory.

4. Economic insights: Various important economic data points are set for release Tuesday.

S&P/Case-Shiller's home price index for May will be released at 9 a.m. ET. This index gives deep insight into the health of America's vast housing market.

Then the Conference Board will release its monthly consumer confidence index at 10 a.m.

5. Monday market recap: U.S. stocks ended the day mixed Monday. The Dow eked out a slight gain while the S&P 500 barely budged and the Nasdaq dipped into negative territory.