Cabaletta Bio, Inc. Annual report [Section 13 and 15(d), not S-K Item 405]

Annual report [Section 13 and 15(d), not S-K Item 405]

Cover
- Document and Entity Information
Financial Statements
Notes to Financial Statements
Accounting Policies
- Summary of Significant Accounting Policies (Policies)
Notes Tables
Notes Details

Fair Value Measurements - Schedule of Debt Securities Classified as Available-for-Sale Investments (Details)

v3.25.1

Fair Value Measurements - Schedule of Debt Securities Classified as Available-for-Sale Investments (Details) $ in Thousands	Dec. 31, 2023 USD ($)
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	$ 241,210
Gross Unrealized Gains	43
Gross Unrealized Losses	(4)
Fair value	241,249
Money Market Funds
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	180,124
Gross Unrealized Gains	0
Gross Unrealized Losses	0
Fair value	180,124
Included in Cash and Cash Equivalents
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	193,234
Gross Unrealized Gains	4
Gross Unrealized Losses	0
Fair value	193,238
Cash
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	743
Gross Unrealized Gains	0
Gross Unrealized Losses	0
Fair value	743
U.S. Treasury securities - original maturity less than three months
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	12,367
Gross Unrealized Gains	4
Gross Unrealized Losses	0
Fair value	12,371
U.S. Treasury securities - due in one year or less
Schedule Of Available For Sale Securities [Line Items]
Amortized Cost	47,976
Gross Unrealized Gains	39
Gross Unrealized Losses	(4)
Fair value	$ 48,011

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