NEW YORK (TheStreet) - It was China and Greece, not oil, which received the bulk of blame for a selloff which saddled U.S. indices with triple-digit losses at one point over Tuesday's session.

"In the first sixty minutes of trading, the run rate was very heavy," UBS' Arthur Cashin told CNBC. "It would project over a billion shares at the end of the day. That indicates to me that some of this selling is coming from offshore, that it's not all domestically grown."

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The S&P 500 hit a one-month low earlier Tuesday, before clawing back to its flatline. The Dow Jones Industrial Average saw its first back-to-back loss since October, down 0.29%. Earlier, the benchmark indices plummeted more than 1% as part of a global market selloff triggered by worries over China's growth prospects and political uncertainty in Greece.

The one shining beacon of Tuesday's was small-caps which managed to pull the Nasdaq and Russell 2000 into positive territory in the afternoon session. The tech-heavy Nasdaq gained 0.54% as shares of biotherapeutic drug developer Bluebird(BLUE) - Get Report spiked 74% on positive results from a recent blood disorder treatment. The Russell added 1.6% as investors picked up bargains among small-cap energy stocks such as Triangle Petroleum (TPLM) , Petroquest (PQ) , Halcon Resources (HK) and Goodrich Petroleum(GDP) - Get Report .

Global growth concerns continued to weigh on Wall Street's mood, though. Greek stocks plummeted as the nation's government expedited its presidential vote by two months to Dec. 17. Prime Minister Antonis Samaris rescheduled the vote after failing to gain support for next year's budget and as eurozone finance ministers granted a two-month extension to unpopular austerity measures. If Samaras fails to gain majority support in the new election, Greece's parliament will be dissolved. National Bank of Greece (NBG) plummeted 13.7%, while the Euro Stoxx 50 ETF(FEZ) - Get Report stumbled 0.87%.

Germany's DAX was down 2.2% as imports fell the most in almost two years, down 3.1% in October and far worse than an estimated 1.5% decline. The data is just the latest worrying sign the eurozone's largest economy is suffering slowing growth and low inflation.

China's Shanghai Composite saw its biggest one-day fall in five years, tanking 5.4%, after Chinese regulators tightened lending rules. Meanwhile, China's Central Economic Work Conference is meeting to determine an official 2015 GDP outlook. World Bank economists are pushing for a growth target forecast of 7%, the lowest level in a decade, so officials can focus on reform plans.

The Federal Reserve passed a proposal to impose risk-based surcharges on top global banks including JPMorgan(JPM) - Get Report , Citigroup(C) - Get Report , Bank of America(BAC) - Get Report and Morgan Stanley(MS) - Get Report . Citigroup was already 0.92% lower after warning of a fourth-quarter $3.5 billion charge, a result of expenses related to Libor and foreign exchange investigations and other restructuring.

Investors were far more concerned on Tuesday with what the Fed could reveal in its monthly meeting next week, particularly whether any indication will be given as to when it could raise interest rates.

"People had started to shift their expectations out to the latter half of 2015 [for a hike], but the good data on employment and especially on the earnings ... really moved people's opinions on what the Fed's going to do," EverBank Wealth Management's Chris Gaffney said in a call. "It's not necessarily a good thing for markets in that the Fed may be coming to an interest rate increase sooner rather than later now."

Oil services stocks regained some ground, including Halliburton(HAL) - Get Report , Baker Hughes (BHI) , and Cameron International (CAM) which sold off recently as West Texas Intermediate plunged below $64 a barrel. "Be very selective on which companies you focus on," Hodges Funds' Eric Marshall said on finding opportunities in the energy selloff. "Look at the [companies] that have the lowest cost production. There are companies out there that can make a good return on capital at $40 or $50 a barrel."

Abercrombie & Fitch(ANF) - Get Report spiked 8% on news long-time CEO Michael Jefferies would step down, effective immediately. The CEO's job had been shaky as plummeting sales and profits caused growing discord among investors

H&R Block(HRB) - Get Report dropped 5% after the tax preparation firm reported a quarterly loss of 45 cents a share, 3 cents wider than expected. AutoZone(AZO) - Get Report shares were up 4.3% after first-quarter revenue climbed more than 8% and earnings beat forecasts.

Conn's(CONN) - Get Report tanked 40.6% as a third-quarter loss of 8 cents a share came in far worse than estimated profits of 68 cents. The company said the loss was due to delinquent accounts at its consumer credit-financing unit.

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-- Written by Keris Alison Lahiff in New York.