Someone held up a 'buy bitcoin' sign during Yellen's testimony to Congress

An unidentified man held up a sign saying "buy bitcoin" during Fed Chair Janet Yellen's testimony Wednesday before the House Financial Services Committee.

Bitcoin subsequently climbed toward session highs and traded 3.5 percent higher, at $2,415, as of 1:03 p.m. ET, according to CoinDesk.

Bitcoin doesn't need the free advertising from this individual. The digital currency has more than doubled in value this year, raising concerns it is entering bubble territory.

Yellen was speaking during the first round of the Fed's semi-annual monetary policy report to Congress and the state of the economy.

Fundstrat's Tom Lee said in a note Friday that central banks may one day buy digital currencies like bitcoin. Lee was the first major Wall Street strategist to issue a report on the cryptocurrency.

Yellen did not comment on cryptocurrency during her testimony.

The unidentified bitcoin proponent, whose stunt was visible on television, was removed from the hearing room.