Jesse Powell, CEO of bitcoin exchange Kraken, said there "could be some crackdown" on cryptocurrencies.
European Central Bank President Christine Lagarde said the bank will not respond to inflation "blips" on Thursday, as prices rise in the euro area.
The European Central Bank could tweak its coronavirus-related stimulus program, Germany's central bank governor told CNBC Wednesday, with officials wary of recent increases in bond yields.
Rising bond yields and accompanying inflation fears are adding a level of drama to Powell's appearance.
European Central Bank President Christine Lagarde hopes 2021 will still be the year of economic recovery post-coronavirus.
The euro rose on Thursday after the European Central Bank unveiled fresh stimulus measures broadly in line with expectations, while sterling fell after post-Brexit trade talks were extended to the weekend in hope of an elusive breakthrough.
The dollar fell on Tuesday to its lowest in more than 2-1/2 years, as investor appetite for risk increased on the prospects of further fiscal stimulus from the United States as well as expectations of a solid global recovery.
The dollar slid for a sixth straight session on Thursday, after trading higher for most of the day, on reports that U.S. Senate Republican leaders have agreed to resume negotiations on another coronavirus stimulus package.
The dollar slipped for a fifth straight session on Wednesday, sliding to a more than one-week low, as positive vaccine news offset the surge in coronavirus cases and tighter economic restrictions across the United States and Europe.
Gold prices eased on Wednesday as optimism about Pfizer's successful vaccine trials countered concerns over rising coronavirus infections and bets for further economic support.
The dollar was little changed on Monday after pharmaceutical firm Moderna became the second U.S. company in a week to report positive results from its COVID-19 vaccine trials.
Gold prices edged higher on Thursday, after dropping over 1% in the previous session, as concerns over the economic fallout from surging Covid-19 cases outweighed positive vaccine news.
The dollar was steady on Tuesday and the yen stayed near three-weeks lows, as investors remained optimistic about progress toward a COVID-19 vaccine and the currency markets digested Monday's big moves.
The safe-haven dollar rose to a four-week high on Friday, moving within narrow ranges, amid jitters ahead of next week's U.S. presidential election and the continued surge in global coronavirus cases that has forced lockdowns in parts of Europe.
The dollar held gains against a basket of major currencies on Thursday as escalating coronavirus cases in Europe stoked investor fears that fresh lockdowns would further hit the already fragile economic recovery.
The dollar hit a seven-week low against a basket of currencies on Wednesday after U.S. President Donald Trump and House Speaker Nancy Pelosi boosted hopes for a large fiscal stimulus package, prompting some traders to ramp up bets on riskier currencies.
Gold edged higher on Tuesday as the dollar weakened and hopes for a U.S. coronavirus aid package ahead of the presidential election boosted bullion's appeal as an inflation hedge.
The dollar kicked off the fourth quarter on a sour note, falling to a more than one-week low on Thursday against a major currency basket, as hopes for U.S. fiscal stimulus cheered investors and spurred them to seek higher-yielding but riskier currencies.
Gold jumped 1% on Thursday to firm above the key $1,900 level on renewed hopes for U.S. stimulus that could help ease the economic pain from the coronavirus, while a weaker dollar also boosted bullion's appeal.
The dollar on Tuesday dropped from last week's two-month highs, as investors capitalized on recent gains in the greenback and cautiously looked ahead to the first debate between U.S. President Donald Trump and Democratic challenger Joe Biden.