** S&P 500 .SPX breaks three-week winning streak, retreats 2.6% as Moody's U.S. credit rating downgrade, fiscal outlook concerns, new tariffs cast a pall .N

** Dow .DJI and Nasdaq Composite .IXIC both decline ~2.5%

** Earlier in week, SPX was streaking toward its highs, while traders gauged Nasdaq's internal tension

** By Friday, IXIC under pressure, gap beckoned after latest Trump tariff salvos

** Benchmark U.S. 10-Year Treasury yield US10YT=RR rose above 4.6% and 30-year yield US30YT=RR surged past ~5% after weak U.S. debt auction reflects tax bill, deficit jitters US/

** Indeed, benchmark Treasury yield hit multi-month highs; at critical juncture; ends week, stepping back to 4.5% area, but still on pace to rise for a 4th week in a row

** Every sector rocked with Energy and Technology most morose

** Energy .SPNY sinks 4.4%. Group slides on Weds after bearish U.S. data on crude and fuel supplies, and drops on Thurs on report OPEC+ discussing more output hikes O/R

Phillips 66 PSX.N falls after split result in proxy fight with Elliott Investment Management

** Tech .SPLRCT stumbles 3.5%. Solar stocks plummet after Trump's tax bill, which may end many green-energy subsidies, advances in U.S. House. Enphase ENPH.O sheds 21%, First Solar FSLR.O dims by ~11%

Apple AAPL.O falls on Fri after Trump says 25% tariffs on iPhones not made in U.S.

Semiconductor index .SOX surrenders 4.5%

** Consumer Discretionary .SPLRCD drops 3.1%. Home Depot HD.N to keep prices steady but says tariffs may make some items unavailable. HD loses ~5% on the week

Hoka-seller Deckers Outdoor DECK.N slumps after scrapping annual targets on tariff worries

** Financials .SPSY flop 3.1%. Big banks fall as Trump tariffs resurface

For the week, S&P 500 banks index .SPXBK off 3.5%, KBW regional banking index .KRX loses ~5%

** Healthcare .SPXHC off 2.1%. At first, vaccine makers up as FDA advisers mull targeting LP.8.1 subvariant in new COVID shots, but then Moderna MRNA.O falls after co withdraws application for COVID-flu combination vaccine. Still, MRNA notches ~6% weekly gain

** Utilities .SPLRCU down 1.6%. Renewables giant NextEra NEE.N falls as Trump's tax bill clears crucial hurdle toward vote on passage in U.S. House

** Communication Services .SPLRCL dip 0.6%. However, Alphabet GOOGL.O jumps on Thurs as investors cheered Google parent's new AI updates

** Consumer Staples .SPLRCS slip 0.4%. Target TGT.N tumbles as tariff pressure, sluggish demand fuel forecast cuts

** Meanwhile, individual investor bulls and bears crisscross

** SPX performance YTD:

(Lance Tupper and Terence Gabriel are Reuters market analysts. The views expressed are their own)

((lance.tupper@tr.com ; terence.gabriel@tr.com))