NEW YORK (TheStreet) -- Bill Gross has successfully squared off against financial market behemoths like the Bank of Japan, the Bank of England and the European Central Bank. As the "Bond King" leaves Pacific Investment Management Company (Pimco) for Janus Capital Group (JNS)  he may find ordinary stock investors a much tougher foe.

So long as Bill Gross has been the Sun God of the bond market, he's only had to answer to investors in his Pimco Total Return Bond Fund(BOND) - Get Report  and his overlords at German insurer Allianz, which owns 70% of Pimco. But that will change with Gross's hasty exit to publicly traded also-ran asset management firm Janus Capital from Pimco, the $2 trillion asset management firm he founded in 1971.

Gross will now have to be accountable to public stockholders in Janus, which carries a market capitalization of just over $2 billion after a 43% Friday surge on news of his hiring. Were the authoritarian tendencies of Gross to carry from Pimco over to Janus, he could find himself the target of scrutiny from public stock investors, and possibly even activist investors who've taken an interest in shaking up publicly traded asset managers.

There's a lot in the way Bill Gross operates that might not sit well with mid-cap stock investors. Gross was reported to have commanded a $200 million a year salary at Pimco, per a 2012 New York Times article. Any figure in that range -- Janus hasn't announced Gross's salary or compensation -- would likely rankle shareholders even after the firm's Friday gain.

Meanwhile, Gross' unceremonious exit from Pimco after 43 years with the firm appears to have come after significant clashes with former CEO Mohamed El-Erian and Pimco's inner circle over his management style. Even loyal bond investors were beginning to desert the King. Gross's Pimco Total Return Bond Fund experienced its sixteenth consecutive month of outflows in September.

Public stock investors might put Gross on a short leash, something he might not be so familiar with after building an empire out of Pimco and operating with near-autonomy within Allianz. Activist investors are also taking a hard look at the performance of asset management firms, which generally continue to generate lukewarm returns even as stock markets rise to new records.

For example, Trian Management has been an activist in Legg Mason(LM) - Get Report for years, taking a seat on the company's board in 2009 and back-channeling for changes to the company's pay structure and top management. Trian also has criticized firms in the financial service sector such as Lazard(LAZ) - Get Report and Bank of New York Mellon(BK) - Get Report .

Perhaps if Gross makes some missteps at Janus it could upset some large shareholders like Japanese insurer Dai-Ichi Life, which holds an about 20% stake in Janus. One wonders how Gross might respond to shareholder concerns, especially after a frantic last year at Pimco.

"While we are grateful for everything Bill contributed to building our firm and delivering value to Pimco's clients, over the course of this year it became increasingly clear that the firm's leadership and Bill have fundamental differences about how to take Pimco forward," Pimco said on Friday.

Gross' first steps at Janus regarding compensation, hiring and his ability to attract new assets may ultimately dictate whether the Bond King will succeed in the new context of a publicly traded money manager. If things go sour, the drama surrounding Gross may rise.

Gross will manage a new fund called the Janus Global Unconstrained Bond Fund, which trades underJUCAX. He will also join Janus's global asset allocation team and drive the company's efforts in global macro fixed-income strategies.

-- Written by Antoine Gara in New York

Follow @AntoineGara