Max Nisen is a Bloomberg Gadfly columnist covering biotech, pharma and health care. He previously wrote about management and corporate strategy for Quartz and Business Insider.

Good morning! This is a preview of Fly Charts, Gadfly's forthcoming newsletter. You can sign up to receive it daily here. From Petrobras lessons to Bush cousins and activist investors, here are four charts that help explain what you need to know in business today. 

Warning Lights
Political woes have stoked doubts about Brazil's debt, testing yield hungry investors who have been pouring into emerging markets.
Source: Bloomberg
Cable Massacre
Charter is hemorrhaging cable subscribers, which makes its acquisition of Time Warner's broadband customers and a possible move into wireless even more important.
Source: Bloomberg
Supercharged
The extreme rise and continuing fall of Petrobras should serve as an object lesson as Saudi Aramco looks to go public.
Source: Bloomberg
Struggle Street
Jonathan Bush's Athenahealth has been posting mediocre profit margins despite ongoing revenue growth, attracting Elliott Management Corp..
Source: Bloomberg

And don't miss Shira Ovide on the lessons of Facebook's IPO, five years later: "First, next time you find yourself doubting Zuckerberg, remember that he has earned the benefit of the doubt. And second, great companies are made, not born. There was nothing preordained about Facebook's rise to a global powerhouse, but rather it was a series of smart decisions large and small."

This column does not necessarily reflect the opinion of Bloomberg LP and its owners.

To contact the author of this story:
Max Nisen in New York at mnisen@bloomberg.net

To contact the editor responsible for this story:
Mark Gongloff at mgongloff1@bloomberg.net