Jane Street’s iShares MBS ETF MBB Stock Holding History

Bought
Maintained
Sold
Quarter Market Value Status Shares Change in
Stake
Trade Value Portfolio Weight Portfolio Position
2026
Q1
$1.53M Buy
16,100
+7,200
+81% +$688K ﹤0.01% 5606
2025
Q4
$847K Sell
8,900
-12,200
-58% -$1.16M ﹤0.01% 6481
2025
Q3
$2.01M Buy
+21,100
New +$1.98M ﹤0.01% 4925
2022
Q2
Sell
-645,000
Closed -$65.7M 10395
2022
Q1
$65.7M Buy
+645,000
New +$67.3M 0.02% 558

Other funds holding MBB

Jane Street's MBB Position: Q1 2026 in Review

Jane Street opened a new position in iShares MBS ETF (MBB) in Q1 2026: 196,999 shares worth $18.7M. The stake represents ﹤0.01% of the portfolio and ranks #1840 among its holdings. This is a return to the name: Jane Street previously reported a position in MBB as recently as Q1 2025.

Jane Street first reported a position in MBB in Q2 2013 and has held it in 33 quarters since. The position peaked at $1.01B in Q2 2021. 1,019 funds tracked by Wall St. Rank hold MBB as of Q1 2026.

  • Jane Street held 196,999 shares of iShares MBS ETF worth $18.7M as of Q1 2026.
  • iShares MBS ETF was a new Jane Street position in Q1 2026.
  • iShares MBS ETF made up ﹤0.01% of Jane Street's portfolio in Q1 2026, its #1840 holding.
  • Jane Street first reported a position in iShares MBS ETF in Q2 2013 and has held it in 33 quarters since.
  • Jane Street's iShares MBS ETF position peaked at $1.01B in Q2 2021.
  • 1,019 funds tracked by Wall St. Rank held iShares MBS ETF as of Q1 2026.

Based on Jane Street's 13F filing for Q1 2026, filed 12 May 2026.