Pacific Biosciences of California, Inc.
MX ˙ BMV ˙ US69404D1081
SecurityMX:PACB / Pacific Biosciences of California, Inc.
InstitutionRhumbline Advisers
Latest Disclosed Ownership348,942 shares
Latest Disclosed Value $ 460,594
Rhumbline Advisers reports 3.33% decrease in ownership of PACB / Pacific Biosciences of California, Inc.

On May 12, 2026 - Rhumbline Advisers filed a 13F-HR form disclosing ownership of 348,942 shares of Pacific Biosciences of California, Inc. (MX:PACB) valued at $460,594 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 13, 2026 disclosing 360,963 shares of Pacific Biosciences of California, Inc.. This represents a change in shares of -3.33% during the quarter.

Institutional Ownership: 13F and NPORT Filings

The Security and Class in the table below are shown exactly as filed by the investor. We do our best to track continuity of investments through acquisitions, and this will be reflected in the table as changes in names. In addition to descriptive data, performance of the investment is shown over time. To calculate quarterly performance, we first calculate cost basis of the shares purchased during the quarter, then use that to calculate gross profit. Quarterly return is Gross Profit / Starting Portfolio value.

Note that cost basis is calculated and stored in thousands, so small quarterly changes in shares frequently result in a cost basis of zero.

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Disclosed Equity Positions (from 13F/NPORT Filings)
File
Date		 Effective
Date		Form Security Class ID Avg Price
Paid (Est)		 Reported
Shares		 ΔShares ΔShares
(%)		 Reported
Value
(x1000)		 ΔValue
(%)		 Alloc
(%)		 ΔAlloc ΔAlloc (%) Cost Basis
(x1000)		 Unrealized
Gain/Loss
(x1000)
2026-05-12 2026-03-31 13F PACIFIC BIOSCIENCES CALIF INC COM COM 69404D108 348,942 -12,021 -3.33 461 -31.75 0.0004
2026-02-13 2025-12-31 13F PACIFIC BIOSCIENCES CALIF INC COM COM 69404D108 360,963 -54,716 -13.16 675 26.69 0.0005
2025-11-06 2025-09-30 13F PACIFIC BIOSCIENCES CALIF INC COM COM 69404D108 415,679 8,532 2.10 532 5.56 0.0004
2025-08-12 2025-06-30 13F PACIFIC BIOSCIENCES CALIF INC COM COM 69404D108 407,147 -31,628 -7.21 505 -2.51 0.0004
2025-05-29 2025-03-31 13F/A-1 PACIFIC BIOSCIENCES CALIF INC COM COM 69404D108 438,775 20,153 4.81 518 -32.51 0.0005
2025-04-08 2025-03-31 13F PACIFIC BIOSCIENCES CALIF INC COM COM 69404D108 438,775 20,153 518 0.0005
2025-05-29 2024-12-31 13F/A-1 PACIFIC BIOSCIENCES CALIF INC COM COM 69404D108 418,622 5,722 1.39 766 9.27 0.0007
2025-01-30 2024-12-31 13F PACIFIC BIOSCIENCES CALIF INC COM COM 69404D108 418,622 5,722 766 0.0007
2024-11-12 2024-09-30 13F PACIFIC BIOSCIENCES CALIF INC COM COM 69404D108 412,900 -23,968 -5.49 702 17.22 0.0006
2024-08-01 2024-06-30 13F PACIFIC BIOSCIENCES CALIF INC COM COM 69404D108 436,868 51,727 13.43 598 -58.59 0.0006
2024-05-09 2024-03-31 13F PACIFIC BIOSCIENCES CALIF INC COM COM 69404D108 385,141 1,823 0.48 1,444 -61.60 0.0014
2024-02-08 2023-12-31 13F PACIFIC BIOSCIENCES CALIF INC COM COM 69404D108 383,318 334 0.09 3,760 17.61 0.0039
2023-11-09 2023-09-30 13F PACIFIC BIOSCIENCES CALIF INC COM COM 69404D108 382,984 1,393 0.37 3,198 -37.00 0.0037
2023-08-08 2023-06-30 13F PACIFIC BIOSCIENCES CALIF INC COM COM 69404D108 381,591 -21,914 -5.43 5,075 126,775.00 0.0057
2023-05-11 2023-03-31 13F PACIFIC BIOSCIENCES CALIF COM 69404D108 403,505 44,460 12.38 5 -99.86 0.0058
2023-02-14 2022-12-31 13F PACIFIC BIOSCIENCES CALIF COM 69404D108 359,045 6,237 1.77 2,937 43.41 0.0039
2022-11-10 2022-09-30 13F PACIFIC BIOSCIENCES CALIF COM 69404D108 352,808 23,329 7.08 2,048 40.66 0.0031
2022-08-11 2022-06-30 13F PACIFIC BIOSCIENCES CALIF COM 69404D108 329,479 92,677 39.14 1,456 -32.44 0.0021
2022-05-12 2022-03-31 13F PACIFIC BIOSCIENCES CALIF COM 69404D108 236,802 -8,272 -3.38 2,155 -57.02 0.0028
2022-02-10 2021-12-31 13F PACIFIC BIOSCIENCES CALIF COM 69404D108 245,074 -3,129 -1.26 5,014 -20.94 0.0061
2021-11-12 2021-09-30 13F PACIFIC BIOSCIENCES CALIF COM 69404D108 248,203 -1,568 -0.63 6,342 -27.39 0.0086
2021-08-05 2021-06-30 13F PACIFIC BIOSCIENCES CALIF COM 69404D108 249,771 34,330 15.93 8,734 21.71 0.0115
2021-05-06 2021-03-31 13F PACIFIC BIOSCIENCES CALIF COM 69404D108 215,441 -8,546 -3.82 7,176 23.51 0.0097
2021-02-10 2020-12-31 13F PACIFIC BIOSCIENCES CALIF COM 69404D108 223,987 27,588 14.05 5,810 199.79 0.0080
2020-11-12 2020-09-30 13F PACIFIC BIOSCIENCES CALIF COM 69404D108 196,399 -15,083 -7.13 1,938 165.48 0.0030
2020-08-13 2020-06-30 13F PACIFIC BIOSCIENCES CALIF COM 69404D108 211,482 17,121 8.81 730 22.69 0.0012
2020-05-06 2020-03-31 13F PACIFIC BIOSCIENCES CALIF COM 69404D108 194,361 -7,119 -3.53 595 -42.57 0.0012
2020-02-05 2019-12-31 13F PACIFIC BIOSCIENCES CALIF COM 69404D108 201,480 3,203 1.62 1,036 1.27 0.0017
2019-10-23 2019-09-30 13F PACIFIC BIOSCIENCES CALIF COM 69404D108 198,277 2,330 1.19 1,023 -13.67 0.0019
2019-08-14 2019-06-30 13F PACIFIC BIOSCIENCES CALIF COM 69404D108 195,947 15,555 8.62 1,185 -9.13 0.0022
2019-05-01 2019-03-31 13F PACIFIC BIOSCIENCES CALIF COM 69404D108 180,392 5,364 3.06 1,304 0.69 0.0025
2019-01-31 2018-12-31 13F PACIFIC BIOSCIENCES CALIF COM 69404D108 175,028 64,940 58.99 1,295 117.28 0.0028
2018-11-07 2018-09-30 13F PACIFIC BIOSCIENCES CALIF COM 69404D108 110,088 -6,872 -5.88 596 43.61 0.0012
2018-08-06 2018-06-30 13F PACIFIC BIOSCIENCES CALIF COM 69404D108 116,960 17,005 17.01 415 102.44 0.0008
2018-05-02 2018-03-31 13F PACIFIC BIOSCIENCES CALIF COM 69404D108 99,955 -1,155 -1.14 205 -23.22 0.0004
2018-02-09 2017-12-31 13F PACIFIC BIOSCIENCES CALIF COM 69404D108 101,110 -7,474 -6.88 267 -53.16 0.0005
2017-11-06 2017-09-30 13F PACIFIC BIOSCIENCES CALIF COM 69404D108 108,584 3,970 3.79 570 53.23 0.0012
2017-08-02 2017-06-30 13F PACIFIC BIOSCIENCES CALIF COM 69404D108 104,614 2,650 2.60 372 -29.41 0.0008
2017-05-02 2017-03-31 13F PACIFIC BIOSCIENCES CALIF COM 69404D108 101,964 2,703 2.72 527 39.79 0.0012
2017-01-27 2016-12-31 13F PACIFIC BIOSCIENCES CALIF COM 69404D108 99,261 6,607 7.13 377 -54.58 0.0010
2016-11-08 2016-09-30 13F PACIFIC BIOSCIENCES CALIF COM 69404D108 92,654 3,819 4.30 830 32.80 0.0023
2016-08-11 2016-06-30 13F PACIFIC BIOSCIENCES CALIF COM 69404D108 88,835 11,802 15.32 625 -4.58 0.0019
2016-05-02 2016-03-31 13F PACIFIC BIOSCIENCES OF CALIF C COM 69404D108 77,033 4,255 5.85 655 -31.49 0.0020
2016-02-03 2015-12-31 13F PACIFIC BIOSCIENCES OF CALIF C COM 69404D108 72,778 7,130 10.86 956 298.33 0.0031
2015-11-04 2015-09-30 13F PACIFIC BIOSCIENCES OF CALIF C COM 69404D108 65,648 -12,358 -15.84 240 -46.55 0.0008
2015-08-04 2015-06-30 13F PACIFIC BIOSCIENCES OF CALIF C COM 69404D108 78,006 980 1.27 449 -0.22 0.0014
2015-05-12 2015-03-31 13F PACIFIC BIOSCIENCES OF CALIF C COM 69404D108 77,026 10,900 16.48 450 -13.13 0.0013
2015-02-06 2014-12-31 13F PACIFIC BIOSCIENCES OF CALIF C COM 69404D108 66,126 11,605 21.29 518 93.28 0.0015
2014-11-12 2014-09-30 13F PACIFIC BIOSCIENCES OF CALIF C COM 69404D108 54,521 -1,300 -2.33 268 -22.32 0.0008
2014-08-06 2014-06-30 13F PACIFIC BIOSCIENCES OF CALIF C COM 69404D108 55,821 -12,673 -18.50 345 -5.74 0.0010
2014-05-06 2014-03-31 13F PACIFIC BIOSCIENCES OF CALIF C COM 69404D108 68,494 -620 -0.90 366 1.39 0.0011
2014-02-03 2013-12-31 13F PACIFIC BIOSCIENCES OF CALIF C COM 69404D108 69,114 -2,400 -3.36 361 -8.61 0.0011
2013-11-05 2013-09-30 13F PACIFIC BIOSCIENCES OF CALIF C COM 69404D108 71,514 -411 -0.57 395 118.23 0.0012
2013-08-07 2013-06-30 13F PACIFIC BIOSCIENCES OF CALIF C COM 69404D108 71,925 71,925 181 0.0006
Legend
Shares
The total number of shares held by the institution at the end of the reporting period (the effective date). This is provided in the filing.
Value
The total value of the shares as of the effective date. This is provided in the filing.
Avg. Share Price
The weighted average share price of the shares held by the institution. We use FIFO accounting to determine this price
Class
This is the security class as indicated by the filer. There are a variety of values for this field. Common values include "EC" = equity common, "EP" - equity preferred
Allocation (%)
The percent of the institution's portfolio that this position represents. This is provided in NPORT filings. For 13F filings, we calculate it.
Change in Allocation
The change in allocation from the prior reporting period. This is calculated as current allocation - prior allocation.
Change in Allocation (%)
The percent change in allocation from the prior reporting period. This is calculated as (current allocation - prior allocation) / prior allocation.
Cost Basis
The total cost of the shares held. This is calculated as reported shares * avg. share price
Unrealized Gain/Loss
This is the market value of the position as of the effective date minus the cost basis.