JPMorgan, Tesla and Donald Trump

Thomson Reuters

U.S. Republican presidential candidate Trump hugs a U.S. flag as he takes the stage for a campaign town hall meeting in Derry

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Back in 1998, the world of finance learned a very painful lesson: Models break and markets aren't efficient.

And, as Business Insider's Myles Udland explains, with the rise of Donald Trump from sideshow to presumptive Republican nominee, politics has learned the same lesson.

JPMorgan just made a big change in its giant investment bank, naming David Hudson to the new role of global head of markets execution. His promotion is part of an effort by JPMorgan to adapt to changing market structures.

The retail industry is transforming, but not the way you think it is, according to Goldman Sachs' global cohead of consumer retail and healthcare banking. And here is the one stat that has every Wall Street banker depressed.

There is a ton of news in the fund management world. Here are the highlights:

• Here's why Jim Chanos is betting against Elon Musk.
• Chanos has a short position in a South Africa-based telecoms company, and it is all because of China.
• Starboard's Jeff Smith has two new targets.
• Zach Schreiber, CEO of PointState Capital, is betting against Saudi Arabia.
• Jeff Gundlach, head of DoubleLine Capital, took a hatchet to the Fed.
• Stanley Druckenmiller thinks the world is heading for a debt-fueled disaster.
• Hedge funds are shaking up the companies behind the brands you know and love.
• Hedge funds have had a torrid time ? here is what they're betting on now.

In other news, a huge wildfire is disrupting oil production in Canada - and now crude is surging. Companies are playing it safe, and it's killing the economy. And Bank of America thinks you should go short humans, long robots.

Lastly, an island resort with a dive center and private beach can be yours for $49 - but there's one catch.

Here are the top Wall Street headlines at midday:

It doesn't matter what Elon Musk says - Tesla's going to raise more cash - Tesla reported better-than-expected first-quarter earnings on Wednesday - and then dropped a bombshell in a letter to shareholders.

Fitbit is getting destroyed - Fitbit shares fell as much as 15% on Thursday after the maker of smart wearables forecast second-quarter revenues lower than analysts expected.

ALBERT EDWARDS: The global economy is like the Titanic and it is about to sink 'below the icy waves' - There are cynics, there are naysayers, and then there's Albert Edwards of Societe Generale, who is in a League of Doom all of his own.

JPMorgan becomes first global bank to fall foul of Hong Kong's stricter IPO sponsorship rules - JPMorgan has become the first global investment bank to fall foul of Hong Kong's stricter IPO sponsorship rules, dealing a blow to its reputation in the region.

EL-ERIAN: Here are 5 reasons why the Fed probably won't do the 'unthinkable' - Not so long ago, negative nominal interest rates were thought unlikely if not unthinkable.

Peter Thiel just sold $101 million of Facebook shares - Peter Thiel, the venture capitalist and PayPal cofounder, sold 857,626 Class A shares in Facebook earlier this week - worth just over $101 million.

This is literally the Ferrari of speedboats - It's a 1990 Riva Ferrari 32, and it is the child of a collaboration between the great Enzo Ferrari and Gino Gervasoni, who was at the time the chairman of Cantieri Riva.