XBI · WMTMT

Jul 13Aug 4Aug 26Sep 17Oct 9

Breadth

108 / 157

stocks fell with the index

Concentration

100%+

of the decline from RARE, QURE, VKTX

Biggest driver

RARE −1.30

ULTRAGENYX PHARMACEUTICAL IN, −53.40%

Biggest offset

MRNA +3.31

MODERNA INC, +235.77%

What drove it

157 members · detractors first · 3M · residual 299.8bp exceeds 60bp gate

The XBI fell 1.02% (−1.59 pts) over the past three months, and more than all of that decline came from just three stocks: RARE, QURE, VKTX.

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

+19.8 pts from 48 gainers−22.3 pts from 109 losers

net −1.6 pts · losers outweigh gainers 1.1 to 1

Stock

Points

Return

XBIsum of all 157 stocks

−1.6

−1.02%

RAREULTRAGENYX PHARMACEUTICAL IN

−1.3

−53.40%

QUREUNIQURE NV

−1.0

−45.04%

VKTXVIKING THERAPEUTICS INC

−0.8

−25.21%

ALKSALKERMES PLC

−0.7

−21.71%

CYTKCYTOKINETICS INC

−0.7

−23.50%

PTCTPTC THERAPEUTICS INC

−0.6

−23.08%

CELCCELCUITY INC

−0.6

−34.54%

MIRMMIRUM PHARMACEUTICALS INC

−0.6

−27.75%

DNTHDIANTHUS THERAPEUTICS INC

−0.5

−16.49%

BBIOBRIDGEBIO PHARMA INC

−0.5

−21.34%

NKTRNEKTAR THERAPEUTICS

−0.5

−45.85%

SRRKSCHOLAR ROCK HOLDING CORP

−0.5

−22.87%

IONSIONIS PHARMACEUTICALS INC

−0.5

−20.21%

PRAXPRAXIS PRECISION MEDICINES I

−0.4

−17.39%

ALNYALNYLAM PHARMACEUTICALS INC

−0.4

−19.23%

127 othersclick to expand the full index

−9.0

ABBVABBVIE INC

+0.3

+12.26%

RXRXRECURSION PHARMACEUTICALS A

+0.4

+32.12%

GILDGILEAD SCIENCES INC

+0.4

+15.05%

AMGNAMGEN INC

+0.5

+15.10%

PURRHYPERLIQUID STRATEGIES

+0.5

+55.17%

PCVXVAXCYTE INC

+0.5

+25.16%

IBRXIMMUNITYBIO INC

+0.5

+34.92%

HALOHALOZYME THERAPEUTICS INC

+0.9

+45.08%

CDNACAREDX INC

+0.9

+121.38%

NTRANATERA INC

+1.1

+46.84%

KODKODIAK SCIENCES INC

+1.2

+142.99%

GRALGRAIL INC

+1.3

+95.79%

TWSTTWIST BIOSCIENCE CORP

+2.1

+76.85%

IOVAIOVANCE BIOTHERAPEUTICS INC

+2.1

+261.88%

MRNAMODERNA INC

+3.3

+235.77%

Cap weighting, illustrated

IMMUNITYBIO INC and REPLIMUNE GROUP INC moved almost identically (+34.92% vs +35.08%), yet IBRX moved the XBI 51.1× 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 −1.59 pt move · cell size = points contributed · color = direction, intensity = return

MRNA+3.3 pts(+235.8%)

IOVA+2.1 pts(+261.9%)

TWST+2.1 pts(+76.8%)

GRAL+1.3 pts

RARE−1.3 pts(−53.4%)

KOD+1.2 pts(+143.0%)

NTRA+1.1 pts(+46.8%)

QURE−1.0 pts

CDNA+0.9 pts

HALO+0.9 pts(+45.1%)

VKTX−0.8 pts(−25.2%)

ALKS−0.7 pts

CYTK−0.7 pts

PTCT−0.6 pts

CELC

MIRM−0.6 pts

DNTH

IBRX

PCVX

BBIO

NKTR−0.5 pts

AMGN+0.5 pts

SRRK−0.5 pts

IONS−0.5 pts

ALNY

DYN

ACAD

CGON−0.4 pts

VERA−0.4 pts

COGT

RXRX

GLUE−0.3 pts

IMVT−0.3 pts

MDGL

37 more

ARWR

RYTM

EXEL

DNLI

ORKA

BIIB

PGEN

CRSP

TNGX

ANAB

XNCR

BCAX

ERAS

COAG

SNDX

BMRN

ANNX

PTGX

RCUS

BEAM

Concentration curve

cumulative share of the −1.59 pt move · sorted by contribution

When they drove it

cumulative points through the period

Breadth

member returns, this period

−100%0%+100%+200%

From −62.01% (CAPR) to +261.88% (IOVA). Equal-weight, the XBI would be −4.41% vs the actual −1.02%; the gap is what cap weighting did.

By sector

point contribution · sums to −1.59 pts

-157

−2.5

The year, session by session

every trading day of 2026 · hover for the move

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SPDR S&P Biotech ETF

What drove it

Attribution map

Concentration curve

When they drove it

Breadth

By sector

The year, session by session

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