Given a document, find the main entity about whom the author is writing. Write the full name if mentioned in the text. Note that URLs in the text have been replaced with [Link].

[EX Q]: Bitcoin's price has fully recovered from  its  recent slump after  JPMorgan CEO Jamie Dimon  called it a fraud and Chinese regulators cracked down on exchanges.
The cryptocurrency had a drawdown of up to 14% in the 10 days after September 12  when  Dimon  compared it to the tulip bubble of the 1600s and vowed to fire traders who used it.
By Thursday  bitcoin had all of the losses. It was up nearly 2% from the lows on the day  Dimon  spoke  at $4157.31 per coin at 10:28 a.m. ET.
The move illustrates bitcoin's wild volatility; it's gained 331% this year  unheard of for any major currency and most financial assets. It also shows why many Wall Street professionals like  Dimon  don't see it as a legitimate store of value but as a speculative instrument.
[EX A]: Jamie Dimon

[EX Q]: FILE PHOTO - U.S. Representative Tim Murphy (R-PA) chairs a House Energy and Commerce Oversight and Investigations Subcommittee hearing on the U.S. response to the Ebola crisis  in Washington October 16  2014. REUTERS/Jonathan Ernst
WASHINGTON (Reuters)  - U.S. Republican Representative Tim Murphy  will resign from Congress on Oct. 21  House Speaker Paul Ryan said on Thursday  following a report alleging that  Murphy  had asked a woman with whom  he  was having an affair to get an abortion.
 Murphy  had said in a statement on Wednesday  he  would not seek re-election next year.  The lawmaker  had been a member of the Congressional Pro-Life Caucus  once receiving a 92 percent score from the conservative Family Research Council  which opposes abortion.
There was no immediate response from  Murphy ’s office for request for comment on Thursday.
The Pittsburgh Post-Gazette  citing a Jan. 25 text message  said the woman had chastised  Murphy  for asking her to get an abortion during a pregnancy scare despite  his  office posting an anti-abortion statement on Facebook.
According to the newspaper   Murphy  texted her in response: “I get what you say about my March for life messages. I’ve never written them. Staff does them. I read them and winced. I told staff don’t write any more. I will.”
 Murphy ’s extramarital affair had first been exposed in 2016 during the woman’s divorce proceedings  the Post-Gazette said.
“This afternoon I received a letter of resignation from Congressman Tim Murphy  effective October 21 ” Ryan said in a statement. “It was Dr.  Murphy ’s decision to move on to the next chapter of his life  and I support it.”
[EX A]: Tim Murphy

[EX Q]: "That was huge to hear that from Todd. He's getting older  and he's coming off back surgery. And I know he wants to be strong at the end of the season " said Giambi  who received interest from the Minnesota Twins before they signed Jim Thome to serve as a designated hitter.
 In his last 20 at-bats with the Rockies last season Giambi knocked in 11 runs. He won multiple games with pinch-hits. But he only plays first base  and hits left-handed  so Colorado wasn't sure he would fit this year's roster.
 "He had an invaluable effect on our club beyond anything I even imagined " O'Dowd said Wednesday. "He really helped teach our younger players what it means to slow the game down."
 In Tulowitzki's case  Giambi is a perfect sounding board. Giambi has lived in the shortstop's shoes  dealt with the pressure of a big contract and huge responsibilities.
 "It's definitely humbling to have this role. You dream about having an impact. I got lucky as a young player to have Mark McGwire help me " Giambi said. "I have obviously had a lot of ups and downs  so I can relate to most guys."
 Giambi's advice is more cerebral than you might think. He discusses situational hitting and how to game plan opposing pitchers. And his passion is infectious  according to teammates.
 "He just has a presence about him. I remember telling people that regardless of what happens  I will get to say I played with Jason Giambi " pitcher Huston Street said. "There's a bigness about his personality and profile  but a smallness in the clubhouse. He doesn't think he's better than anybody else and he really cares."
 But Giambi is in Colorado not just because he fits  but because he believes the team can win a ring  something that eluded him with the Yankees.
 "We better kick some (butt) this year " Giambi said. "I didn't come here to finish second. I came back to win a championship."
[EX A]:
Jim Thome