(Read more: Moore Capital set to hire SAC traders)
Karp's Tourbillon Capital Partners is a prime example.
Karp worked at SAC's CR Intrinsic unit from 2005 to 2009, where he was a generalist portfolio manager and director of research. After a stop as co-chief investment officer of Carlson Capital, Karp launched his own long/short equity hedge fund firm on Jan. 14, 2013 with about $250 million under management, half of it from U.K. pension funds.
Tourbillon has sucked in assets ever since.
The firm managed $750 million as of Jan. 1, according to a person familiar with the situation, and plans to add about $250 million more from investors over the second quarter. The fund plans to stop all new investment at about $1 billion, known as a "hard close."
Investors were evidently focused on Karp's investing skills. Tourbillon's flagship fund gained 20.7 percent net of fees in 2013, about the same as at SAC and nearly twice the return of the Absolute Return Global Equity Index, which gained 11.85 percent through November.
Impressively, the return was accomplished with an average net exposure over 2013 of 14.5 percent, meaning Tourbillon long bets on stocks barely outweighed its shorts. Some of the best performing hedge funds had exposures closer to 35 percent or 40 percent as of December.
Successful long trades included Japanese tech company SoftBank and Chinese online travel business Ctrip.com, according to investor letters obtained by CNBC.com.
Amy Zipper, Tourbillon's chief operating officer, declined to comment.
(Read more: No letup on risk for hedge funds this December)
Cowen's Suvretta Capital Management is another fast-rising fund run by an SAC alum.
Cowen worked as chief investment officer at SAC from 2008 to 2010, where he co-managed the firm's multi-billion dollar central investment portfolio with Cohen himself.
After time at Soros Fund Management in between, Cowen launched Suvretta, a long/short equity focused firm. The shop's funds opened to outside capital in October 2012 and attracted $165 million as of Jan. 1, 2013.
But thanks to a strong 26.3 percent net gain in 2013, the firm has more than $700 million as of Jan. 1 this year, according to investor materials obtained by CNBC.com. Cowen declined to comment.
(Read more: Hot new eBay item: SAC Capital polar fleece)
A third example is Shaver's Electron Capital Partners.
The firm's utility and infrastructure stock-focused team and strategy was part of SAC from 2008 to 2012 and managed an average of$1.3 billion. Shaver spun out and opened Electron to external investors on May 1 with $20 million.
Electron has already grown to $191 million after gaining 14.72 percent net of fees from March through December 2013, according to investor materials obtained by CNBC.com. That's more than double the MSCI World Utilities Index gain of 7.20 percent over the same period. Recent winners include long bets on the stocks of energy companies NRG Yield and Pattern Energy. Shaver declined to comment.
Of course, not all SAC alums have fared as well.
Paul Orwicz, a portfolio manager at SAC for 11 years, left to launch Sursum Capital Management in March 2010 and raised significant assets to run $720 million by April 2011. But double-digit losses in 2011 causes Orwicz to shut the long/short equity firm and rejoin SAC.
(Read more: Jury finds SAC Capitol Advisors' Michael Steinberg guilty)
A more recent stumble came at Adams Hill Partners, run by SAC alum Andrew Schwartz. An SAC portfolio manager from 2004 to 2012, Schwartz raised $334 million from investors as of Dec. 1, 2013 after launching in January 2013.
But redemptions could come after his industrials, mining and materials-focused fund performed poorly in 2013, losing 8.58 percent through November, according to investor materials obtained by CNBC.com. Recent losers for the low-net exposure fund were short bets on two unnamed chemical companies and a refining company.
Adams Hill didn't respond to a request for comment.
Regardless, observers don't expect investors to automatically reject the funds of future SAC alums. Recent or planned launches have come from SAC portfolio manager David Vogt's Point Harbor Partners and Anil Stevens, who co-managed recently-shut SAC unit Parameter Capital Management.
"There is very little sense of stigma," said one investor consultant who tracks hedge fund launches closely.
SAC has been reeling from a string of insider trading convictions and settlements. Most recently, portfolio manager Michael Steinberg was found guilty on Dec. 18 for various violations. He faces time in prison. Another, Mathew Martoma, faces trial imminently.
In early November, SAC pleaded guilty to criminal insider trading charges and agreed to pay a $1.2 billion fine. Cohen, who has not been personally charged with any crime, also agreed to stop managing outside capital. That was on top of a $616 million fine by the Securities and Exchange Commission for related charges.
(Read more: Trial to Begin for Ex-SAC Trader Who Cut No Deal)
A spokesman for SAC didn't respond to a request for comment, but a recent SAC statement made clear it didn't believe there was a culture of corruption, as the government alleged.
"We take responsibility for the handful of men who pleaded guilty and whose conduct gave rise to SAC's liability," the firm said on Nov. 4, 2013. "These wrongdoers do not represent the 3,000 honest men and women who have worked at the firm during the past 21 years."