What you need to know on Wall Street right now

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The rise of passive investing has fundamentally altered the business of Wall Street.

It is changing money management, as dollars flow from actively managed funds to index-tracking funds. It has changed stock trading.

And now, it may also be changing the quality of research produced by investment banks for active-investment firms like hedge and mutual funds.

Elsewhere on Wall Street, the business of trading corporate bonds has changed, and the Fed admitted that a startup can predict its upcoming interest rate forecasts.

Wells Fargo has fired thousands of employees and incurred fines totaling $185 million because of a widespread practice of employees opening new accounts for existing customers without their authorization. Business Insider's Josh Barro argues that the scandal is a cautionary tale about incentive pay.

The bond king, Jeff Gundlach, is back with a new presentation on the markets and economy. He says it's time to be defensive on bonds, and thinks the dollar could fall.

And finally, Cairn Capital, a London-based fund management firm with $8.6 billion in assets under advice, has made a big hire.

In deal news, a startup worth over $1 billion had $83 million in revenue last year - and it just filed to go public. And after spending $4 billion on acquisitions this year, Salesforce bought yet another company.

Elsewhere, the explosion of student debt could be "a drag on the financial well-being of the nation," and the stock market is finally moving again after a long quiet stretch.

Finally, here's a great interview with legendary physicist Freeman Dyson, who talks about math, nuclear rockets, and astounding things about the universe.

Here are the top Wall Street headlines at midday:

Chinese buyers are getting real savvy - Chinese investors have been aggressively pursuing acquisitions, in a move that is unsettling to many.

The little guys are winning on Wall Street - It doesn't take a position at a big investment bank to land a role on a big deal.

Here's who holds the world's $60 trillion in sovereign debt - The world's governments now have around $60 trillion in debt which is then sold to investors as bonds. So who owns this debt?

The 'Barbarians at the Gate' are getting something right - There is a long running debate in private equity investing.

Morgan Stanley isn't so sure about its forecast for the oil recovery anymore - Morgan Stanley is losing its conviction about the oil market's future.

San Francisco's housing market has been on a 'wild ride' - The housing market in San Francisco has a notorious reputation.

Porsche just unveiled a new model of its Panamera hybrid - and it looks amazing - Porsche unveiled a new version of its hybrid sedan Friday and it comes with some impressive new features.

RANKED: The 10 busiest airports in the world - The Airports Council International (ACI) released its 2015 World Airport Traffic Report on Friday.