What you need to know on Wall Street right now

Finance Insider is Business Insider's summary of the top stories of the past 24 hours.

The warning signs for the global economy are stacking up.

• The world's largest maker of massive industrial equipment lowered its 2016 earnings forecast on Tuesday, saying it did not expect economic conditions or its key industries to improve.
• The restaurant sector could be sending a warning sign about the US economy.
• The service sector is growing at the weakest pace in 5 months.
• Asia could be walking into a financial disaster.
• Stand by for the Fed to do nothing later today.

Everyone on Wall Street is talking about a small, secretive hedge fund that is posting crazy returns. Billionaire investor Steve Cohen has a new mantra, and this is the guy enforcing it. And David Einhorn is back on his jelly donut kick.

Apple will report quarterly earnings this afternoon, and if it misses this key number, it means Tim Cook is misjudging his business.

The CFA Level 1 and 2 results are in.

Finally, the king of New York City's power lunch may have closed, but a fan just bought its sign for $96,000.

Here are the top Wall Street headlines at midday:

Goldman Sachs is having a rough week - The private equity firm Primus Pacific Partners - a shareholder of one of Goldman's clients, the Malaysian bank EON Capital - is suing the firm for $510 million.

The hedge fund industry has a 'real problem,' but it's not the one you think - The hedge fund industry is struggling.

Marc Benioff tried to buy LinkedIn even after it announced the deal with Microsoft - After LinkedIn officially announced that it had sold itself to Microsoft for $26.2 billion in cash last month, Salesforce CEO Marc Benioff, a rival bidder, didn't give up right away.

David Einhorn closed his investor letter with an interesting quote about Tesla - Greenlight Capital founder David Einhorn placed an interesting quote about Tesla at the end of this second-quarter investor letter.

Here's why investing in China is 'crazy ... literally' - For those who have been following Asian markets for some time, Taiwan and China are looking awfully similar.

A Silicon Valley banker says this is the most surprising trend he's seen in healthcare - The travails of Theranos - once a Silicon Valley favorite, now a poster child for what can go wrong with hot startups - have done nothing to slow investment in the healthcare sector.

Silicon Valley's legendary investors are stuck in the past - It turns out that corporate governance is about more than just lawyers endlessly droning on about Delaware law after all.