WMTMT◆
WHAT MOVED THE MARKET TODAY
DAILY NOTES

SPDR S&P Biotech ETF

157 stocks · cap-weighted, ETF-derived weights · Oct 9, 2026 close
153.75
+48.31 (+45.82%)
XBI 153.75 · +48.3 pts (+45.82%) 1Y
1D1W1MQTD3M6MYTD1Y2Y3Y5Y
210.05181.87153.69125.51EW +66.56%H 169.55 · Aug 19L 104.99 · Oct 10
Oct 8, 2025Jan 8, 2026Apr 10, 2026Jul 13, 2026Oct 9, 2026
Breadth
92 / 157
stocks rose with the index
Concentration
20%
of the gain from MRNA, TWST, IOVA
Biggest driver
MRNA +3.99
MODERNA INC, +705.87%
Biggest drag
ALNY −2.49
ALNYLAM PHARMACEUTICALS INC, −48.37%

What drove it

157 members · drivers first · 1Y · residual 1342.5bp exceeds 60bp gate

The XBI rose 45.82% (+48.31 pts) over the past year on a mixed tape; MRNA, TWST, IOVA did most of the lifting, with 20% of the gain between them.

Read the latest market-close note: Goldman and Microsoft Push the Dow to a Large Gain While Telecoms Sink Communication Services

+62.2 pts from 95 gainers−15.8 pts from 62 losers
net +48.3 pts · gainers outweigh losers 3.9 to 1
Stock
Points
Return
XBIsum of all 157 stocks
+48.3
100%
+45.82%
MRNAMODERNA INC
+4.0
8%
+705.87%
TWSTTWIST BIOSCIENCE CORP
+3.3
7%
+387.28%
IOVAIOVANCE BIOTHERAPEUTICS INC
+2.5
5%
+544.05%
ERASERASCA INC
+2.2
4%
+559.67%
IBRXIMMUNITYBIO INC
+2.0
4%
+315.42%
NTRANATERA INC
+2.0
4%
+132.85%
GRALGRAIL INC
+1.9
4%
+93.13%
SYRESPYRE THERAPEUTICS INC
+1.8
4%
+384.67%
KODKODIAK SCIENCES INC
+1.8
4%
+590.66%
KRYSKRYSTAL BIOTECH INC
+1.5
3%
+77.16%
CDNACAREDX INC
+1.5
3%
+330.49%
RVMDREVOLUTION MEDICINES INC
+1.4
3%
+296.82%
ORKAORUKA THERAPEUTICS INC
+1.3
3%
+263.08%
PTGXPROTAGONIST THERAPEUTICS INC
+1.3
3%
+120.11%
SLSSELLAS LIFE SCIENCES GROUP I
+1.3
3%
+503.63%
127 othersclick to expand the full index
+28.2
58%
·
ADMAADMA BIOLOGICS INC
−0.3
−1%
−29.14%
LXEOLEXEO THERAPEUTICS INC
−0.3
−1%
−59.78%
MNKDMANNKIND CORP
−0.3
−1%
−39.52%
SPRYARS PHARMACEUTICALS INC
−0.4
−1%
−61.93%
MLYSMINERALYS THERAPEUTICS INC
−0.4
−1%
−37.66%
STOKSTOKE THERAPEUTICS INC
−0.4
−1%
−18.89%
NTLAINTELLIA THERAPEUTICS INC
−0.4
−1%
−46.59%
RAREULTRAGENYX PHARMACEUTICAL IN
−0.4
−1%
−49.84%
NKTRNEKTAR THERAPEUTICS
−0.5
−1%
−45.85%
SRPTSAREPTA THERAPEUTICS INC
−0.7
−1%
−23.65%
SMMTSUMMIT THERAPEUTICS INC
−0.8
−2%
−24.64%
IONSIONIS PHARMACEUTICALS INC
−0.9
−2%
−35.28%
INSMINSMED INC
−1.1
−2%
−37.83%
QUREUNIQURE NV
−2.2
−5%
−62.33%
ALNYALNYLAM PHARMACEUTICALS INC
−2.5
−5%
−48.37%
Cap weighting, illustrated

VERACYTE INC and ALKERMES PLC moved almost identically (+28.86% vs +28.88%), yet VCYT moved the XBI 125.1× as much. In a cap-weighted index, the bigger company's weight turns the same percentage move into far more points.

Attribution map

slicing the +48.31 pt move · cell size = points contributed · color = direction, intensity = return
MRNA+4.0 pts(+705.9%)
TWST+3.3 pts(+387.3%)
ALNY−2.5 pts(−48.4%)
IOVA+2.5 pts(+544.1%)
QURE−2.2 pts
ERAS+2.2 pts
IBRX+2.0 pts
NTRA+2.0 pts(+132.8%)
GRAL+1.9 pts(+93.1%)
SYRE+1.8 pts(+384.7%)
KOD+1.8 pts
KRYS+1.5 pts
CDNA+1.5 pts(+330.5%)
RVMD+1.4 pts(+296.8%)
ORKA+1.3 pts(+263.1%)
PTGX+1.3 pts
SLS+1.3 pts
TVTX
VCYT+1.3 pts(+28.9%)
TGTX+1.2 pts(+54.9%)
DNTH+1.2 pts(+137.0%)
BEAM+1.2 pts
ROIV+1.1 pts
KYMR+1.1 pts
INSM−1.1 pts
HALO
ARWR+1.0 pts
EXEL+0.9 pts
IONS
PCVX
PURR
RLAY+0.8 pts
NVAX+0.8 pts
SMMT−0.8 pts
BIIB+0.7 pts
INCY
COGT
AMGN
SRPT
IMVT
ABSI
GILD
CGON
TNGX
CRSP
NKTR
CYTK
ZBIO
VRTX
REGN
PTCT
XNCR
NTLA
MLYS
SPRY
INBX
ADMA
ARDX

Concentration curve

cumulative share of the +48.31 pt move · sorted by contribution
0%50%100%3979118157stocks:3 stocks = 20%100% covered at 35

When they drove it

cumulative points through the period
0MRNA +3.99TWST +3.31IOVA +2.46ALNY −2.49QURE −2.22INSM −1.10Oct 8Oct 9

Breadth

member returns, this period
−100%+100%+300%+500%+700%
From −74.54% (CMPX) to +705.87% (MRNA). Equal-weight, the XBI would be +66.56% vs the actual +45.82%; the gap is what cap weighting did.

By sector

point contribution · sums to +48.31 pts
-157
+46.4

The year, session by session

every trading day of 2026 · hover for the move
JANFEBMARAPRMAYJUNJULAUGSEPOCT

Share this move

pick a view, download it as a 16:9 PNG
What moved the market, in your inbox
The daily note publishes here after every close; the week's story lands in your inbox on Fridays, free. Read the daily notes.
Babylon Burns

WMTMT is built by the founders of Babylon Burns, a letter on markets, macro, and the systems behind them. The numbers live here; the arguments live there. Subscribing below joins the Babylon Burns letter.

SESSIONSETTLEDBOARDXBI 1YMEMBERS157RESIDUAL1342.5BP / 60BP GATESRCNASDAQ · CBOE · ALPHA VANTAGEWMTMT.COM