By Trevor Hunnicutt

NEW YORK (Reuters) - Record cash streamed out of U.S.-based stock funds and billions more fled bonds in a week of apparently escalated caution, Lipper data showed on Thursday.

More than $46 billion thundered out of U.S. stock mutual funds and exchange-traded funds (ETFs), the most ever, while a near-record $13 billion poured from bonds, according to the research service. Relatively low-risk money market funds pulled in $81 billion, also the most recorded, the research service's data showed.

The withdrawals appeared to show investor confidence cracking in the waning days of a wild year of up-and-down trading that has left many people with losses across both stock and bond funds, a rare occurrence.

The end-of-year numbers could also reflect changes related to capital gains distributions and as investors re-evaluate their holdings for tax reasons and other purposes, though in other years the volume has not been this high in a single week.

U.S. Federal Reserve rate hikes, high corporate borrowing, rising relative yields on short-term bonds, U.S.-China trade tensions and slowing growth in corporate profits have left investors with much to stew over. The average U.S.-based equity fund is down 6.3 percent in the year through Dec. 11, while its bond counterpart is down 0.9 percent, Lipper said.

More than $45 billion of the withdrawals came from equity mutual funds, heavily used by retail investors during the week. Lipper measures a week as the seven-day period from Thursday to Wednesday, and much of its records date back to 1992.

Individual investors are the most pessimistic about stock performance they have been in more than five years, with 49 percent expecting the market to fall in the next six months, according to a widely-followed survey by the American Association of Individual Investors covering the latest week.

(Reporting by Trevor Hunnicutt in New York; Editing by Jennifer Ablan and Rosalba O'Brien)