GS Blekos Marketcolour

GS Ioannis Blekos - Marketcolour + US Trading Webcast / Argenx / Flutter / Unibrew / Swissquote 18 Aug 2026 Ioannis Blekos · Goldman Sachs · Executive Director, Global Banking & Markets Tue 18 Aug 2026, 2:33am ET

US equities were lower to start the week, ending near session lows, as higher yields and oil following escalatory US-Iran news flow pressured risk: SPX -52bps to 7745 (1/11 sectors +ve, Energy +87bps, VIX @15.19 +6%, SOX +1.64%, SPW vs SPX -37bps), NDX -17bps to 29,995, RTY -35bps to 3057. High Beta Momo (GSPRHIMO, +496bps) rose as Memory (GSTMTMEM, +384bps) gained (SNDK +8.9% leading the group higher). In Europe, the semi/software divergence was the dominant intraday theme. EU Semis (GSSBSEMI +2.4%, ASML NA +2.6%, ASM NA +1%, BESI NA +1.8%, STMMI FP +5%) vs Software (GSSBSFTW –1.2%, SAP GY -30bps, DSY FP -1.4%).

Deriv Flow: Dealers were long $15bn of gamma (99th percentile) after Friday's session, and we estimate that level held, with dealers even getting slightly longer. Yesterday, we saw hedges and non AI shorts picking up as long end yields continue to drift wider.

Buybacks: Our desk saw robust and steady volumes last week driven by the ongoing corporate open window. Last week’s flows finished at 1.5x vs 2025 YTD ADTV and 1.4x vs 2024 YTD ADTV skewed toward Tech, Financials, and Health Care sectors. We currently estimate 96% of the S&P 500 are in an open window period. With over $1T in buyback authorizations announced, corporate demand is estimated to remain over the summer.

GS Invite: US Equity Flow & Positioning Webinar: Wednesday Aug 19th 1pm EST / 6pm BST (review YTD and MTD flow, performance & positioning color, geopolitics, rates, and TMT EPS).

Rates: Monday saw the yield on the 30-year US Treasury top 5.3% for the first time since the eve of the Global Financial Crisis in 2007, and that’s in line with global experience; Japanese 30-year yields have risen above 4% for the first time in their 27-year history, while equivalent UK gilts yield their highest since 1998. Chart below.

Argenx (CL BUY / PT EUR973 / 33% Upside): Following positive topline data from the ALKIVIA trial investigating Vyvgart in myositis and subsequent analyst call, we update our model and raise our price targets by 7%/7% to €973/$1,145 (vs €907/$1,067 previously) and remain Buy rated (on CL).