On 11 September 2001 BGC Partners lost 658 colleagues in the attacks on the Twin Towers.
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Every year, amid the sorrow, they commemorate those people - and all the victims of that day - by donating their global revenues to the Cantor Fitzgerald Relief Fund and hundreds of other charities.
And today a host of well-known faces turned out for BGC's Charity Day, taking their turn on the trading floor in New York.
The likes of American actors Samuel J Jackson and Steve Bushemi sealed deals alongside Princess Beatrice and television and radio presenter Jonathan Ross.
Girl band All Saints were present helping to raise money for Marie Curie Cancer Care, while model Twiggy was supporting Grief Encounter, which helps bereaved children.
Meanwhile Countdown's Rachel Riley celebrated her deal on behalf of children's hospital Great Ormond Street.
Since its inception, Charity Day has raised approximately $101 million globally.
Also today, politicians, dignitaries and victims' relatives gathered in New York City, at the Pentagon, and in rural Pennsylvania to remember the nearly 3,000 people killed in the attack 13 years ago.
BGC Charity Day 2014
BGC Charity Day 2014
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Actor Steve Bushemi attends Annual Charity Day hosted by Cantor Fitzgerald and BGC at BGC Partners, INC on 11 September, 2014 in New York City
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Princess Beatrice is seen smiling on the trading floor
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Actor Samuel L Jackson looks pleased with his efforts
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Comedian Jennifer Saunders looks as though she's bitten off more than she can chew...
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...But funny man Jack White takes it one step further
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Model and TED speaker Cameron Russell steps up to the board
Speaking at the Pentagon during a private ceremony for relatives of the 184 people killed in the attack on the headquarters of the US Defence Department, Obama said: "Thirteen years after small, hateful minds conspired to break us, America stands tall and America stands proud."
He added that love was "the ultimate rebuke to the hatred of those who attacked us that bright, blue morning."Reuse content