U.S. equity index futures modestly higher Euro STOXX 600 index gains ~0.7% Dollar, gold, crude all rise slightly; bitcoin ~flat U.S. 10-Year Treasury yield ~1.46% Dec 23 - Welcome to the home for real-time coverage of markets brought to you by Reuters reporters. You can share your thoughts with us at markets.research@thomsonreuters.com VOLATILITY IN THE TIME OF OMICRON (0927 EST/1427 GMT) As the last trading day before Christmas gets underway, the S&P 500 has posted moves of at least 1% in either direction for the four straight prior sessions -- rising by at least 1% for past two days, after falling by at least that amount in the two days before. Indeed, the benchmark index has swung by at least 1% in nine of the 16 full sessions so far in December. As it stands, the S&P 500"s average move of 1.1% would make it the fourth-rockiest December since 1987, according to Art Hogan, chief market strategist at National Securities. Only 2018, 2008 and 2000 had bigger average December moves, per Hogan. Hogan says in a note that the volatility stems from "three well disseminated concerns": a more hawkish Fed, the "shelving" of President Joe Biden"s "Build Back Better" investment bill, and fears the spread of the Omicron coronavirus variant could derail the economy. Yet even with that volatility, as of Wednesday"s close, the S&P 500 was up 2.8% in December, and 25% for 2021. Hogan writes: "With many of the current market concerns well known, and arguably well priced in at both the index, and more prominently at the average stock level, we would suggest markets have done an overly efficient job in selling the rumor, and will likely start buying the news." (Lewis Krauskopf) ***** NASDAQ 100: ON THE FLIP SIDE OF A FLOP (0900 EST/1400 GMT) The Nasdaq 100 (.NDX) is currently up 0.27% for the month of December. That puts it on track for its smallest monthly rise since November 2016. That said, it"s not that there hasn"t been volatility this month. In fact, there has been significant flip-flopping on a weekly basis. This week, the NDX is on track to rise 2.4%. read more Over the preceding three weeks, the index of the one hundred largest non-financial companies on the Nasdaq fell 2%, surged 4%, and then slid 3.2%. Of note, on the downside, the rising 20-week moving average (WMA) has proven to be resilient support since it was reclaimed in April 2020 read more : NDX12232021 NDX12232021 More recently, the early-December 4% surge came after an NDX slide that ended just 1.6% above the 20-WMA. This week"s rally is coming after the index declined and finished last Friday just 1.5% above the moving average. Meanwhile, the 20-WMA, which is now around 15,625, will likely ascend to around 15,680 next week. A resistance line from the July 2020 20-WMA disparity high will then be residing around 7.1% above the moving average, which will equate to around 16,793 on the NDX. This should add to the wall of resistance at the NDX"s Nov. 19 record close of 16,573.343 and Nov. 22 record intraday high of 16,764.855. A disparity break out above the resistance line could suggest the NDX could accelerate further into record-high territory. Conversely, a more decisive closing break of the 20-WMA than was seen in late-October 2020 (or more than -0.1%), with the moving average then ticking down, could instead lead to a sea change in trend, to the downside. read more (Terence Gabriel) ***** FOR THURSDAY"S LIVE MARKETS" POSTS PRIOR TO 0900 EST/1400 GMT - CLICK HERE: read more