Tearsheet

Investment Highlights Why It Matters Which of these 2 stories sounds closer for this stock?

1. Generates cash flow

The stock generated 4% or more of the share price (called cash flow yield), and shows moderate 10-15% or more growth.

2. Riding a trend

Think Tesla during the pandemic of 2020 when EVs were riding a cultural high, or Nvidia in the current AI boom, or even Figma. These companies don’t have enough yield, or, enough growth, or both - however - they are riding a trend. They have momentum. These can be more volatile - they don’t have the floor of strong cash flow


0 Cash is significant % of market cap
Net D/ENet Debt/Equity. Debt net of cash. Negative indicates net cash. Equity is taken as the Market Capitalization is -44%
Weak multi-year price returns
2Y Excs Rtn is -135%
Not profitable at operating income level
Op Inc LTMOperating Income, Last Twelve Months is -99 Mil, Op Mgn LTMOperating Margin = Operating Income / Revenue Reflects profitability before taxes and before impact of capital structure (interest payments). is -1569%
1 Valuation becoming less expensive
P/S 6M Chg %Price/Sales change over 6 months. Declining P/S indicates valuation has become less expensive. is -88%
Meaningful short interest
Short Interest % of Basic SharesShort Interest % of Basic Shares = (Short Interest Quantity) / (Basic Shares Outstanding). A high fraction of short interest can indicate potential risk of a short squeeze. is 15%
Not cash flow generative
CFO/Rev LTMCash Flow from Operations / Revenue (Sales), Last Twelve Months (LTM) is -1071%, FCF/Rev LTMFree Cash Flow / Revenue (Sales), Last Twelve Months (LTM) is -1176%
2 Megatrend and thematic drivers
Megatrends include Biotechnology & Genomics, and Precision Medicine. Themes include Gene Editing & Therapy, and Targeted Therapies.
  Yield minus risk free rate is negative
ERPEquity Risk Premium (ERP) = Total Yield - Risk Free Rate, Reflects the premium above risk free assets offered by the investment. is -82%
3   High stock price volatility
Vol 12M is 132%
0 Cash is significant % of market cap
Net D/ENet Debt/Equity. Debt net of cash. Negative indicates net cash. Equity is taken as the Market Capitalization is -44%
1 Valuation becoming less expensive
P/S 6M Chg %Price/Sales change over 6 months. Declining P/S indicates valuation has become less expensive. is -88%
2 Megatrend and thematic drivers
Megatrends include Biotechnology & Genomics, and Precision Medicine. Themes include Gene Editing & Therapy, and Targeted Therapies.
3 Weak multi-year price returns
2Y Excs Rtn is -135%
4 Meaningful short interest
Short Interest % of Basic SharesShort Interest % of Basic Shares = (Short Interest Quantity) / (Basic Shares Outstanding). A high fraction of short interest can indicate potential risk of a short squeeze. is 15%
5 Not profitable at operating income level
Op Inc LTMOperating Income, Last Twelve Months is -99 Mil, Op Mgn LTMOperating Margin = Operating Income / Revenue Reflects profitability before taxes and before impact of capital structure (interest payments). is -1569%
6 Not cash flow generative
CFO/Rev LTMCash Flow from Operations / Revenue (Sales), Last Twelve Months (LTM) is -1071%, FCF/Rev LTMFree Cash Flow / Revenue (Sales), Last Twelve Months (LTM) is -1176%
7 Yield minus risk free rate is negative
ERPEquity Risk Premium (ERP) = Total Yield - Risk Free Rate, Reflects the premium above risk free assets offered by the investment. is -82%
8 High stock price volatility
Vol 12M is 132%

Valuation, Metrics & Events

KRRO Stock


Why The Stock Moved


Qualitative Assessment

AI Generated Analysis | Feedback

Here are the key points for why Korro Bio's (KRRO) stock moved by -73.8% from approximately August 31, 2025, to December 4, 2025:

1. Disappointing Clinical Trial Results for KRRO-110. Korro Bio's stock plummeted after the company reported mixed results from its Phase 1/2a REWRITE clinical trial for KRRO-110, an Alpha-1 Antitrypsin Deficiency (AATD) treatment. While the drug produced functional protein, it failed to reach the projected therapeutic levels needed, achieving only about 2 µM of M-AAT protein, significantly below the protective threshold of 11 µM.

2. Strategic Restructuring and Workforce Reduction. In response to the disappointing trial outcomes, Korro Bio announced a strategic restructuring plan, including a reduction of approximately 34% of its workforce. This move was intended to extend the company's cash runway into the second half of 2027.

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Stock Movement Drivers

Return vs. Risk


Price Returns Compared

 202020212022202320242025Total [1]
Returns
KRRO Return101%-85%-25%1145%-21%-86%-70%
Peers Return2%-1%6%8%-0%2%17%
S&P 500 Return16%27%-19%24%23%16%112%

Monthly Win Rates [3]
KRRO Win Rate50%42%50%33%42%50% 
Peers Win Rate13%8%13%12%10%90% 
S&P 500 Win Rate58%75%42%67%75%70% 

Max Drawdowns [4]
KRRO Max Drawdown-16%-86%-80%-94%-35%-86% 
Peers Max Drawdown-2%-5%0%-0%-1%-2% 
S&P 500 Max Drawdown-31%-1%-25%-1%-2%-15% 


[1] Cumulative total returns since the beginning of 2020
[2] Peers: VRTX, AIXC, ALPS, BBOT, EVMN.
[3] Win Rate = % of calendar months in which monthly returns were positive
[4] Max drawdown represents maximum peak-to-trough decline within a year
[5] 2025 data is for the year up to 12/3/2025 (YTD)

How Low Can It Go

Unique KeyEventKRROS&P 500
2022 Inflation Shock2022 Inflation Shock  
2022 Inflation Shock% Loss% Loss-99.6%-25.4%
2022 Inflation Shock% Gain to Breakeven% Gain to Breakeven25308.8%34.1%
2022 Inflation ShockTime to BreakevenTime to Breakeven35 days464 days
2020 Covid Pandemic2020 Covid Pandemic  
2020 Covid Pandemic% Loss% Loss-46.8%-33.9%
2020 Covid Pandemic% Gain to Breakeven% Gain to Breakeven88.1%51.3%
2020 Covid PandemicTime to BreakevenTime to Breakeven220 days148 days

Compare to VRTX, AIXC, ALPS, BBOT, EVMN


In The Past

Korro Bio's stock fell -99.6% during the 2022 Inflation Shock from a high on 2/19/2021. A -99.6% loss requires a 25308.8% gain to breakeven.

Preserve Wealth

Limiting losses and compounding gains is essential to preserving wealth over time.

Asset Allocation

Actively managed asset allocation strategies protect wealth. Learn more.

About Korro Bio (KRRO)

Better Bets than Korro Bio (KRRO)

Latest Trefis Analyses

Title
0ARTICLES

Trade Ideas

Select past ideas related to KRRO. For more, see Trefis Trade Ideas.

Unique KeyDateTickerCompanyCategoryTrade Strategy6M Fwd Rtn12M Fwd Rtn12M Max DD
CRL_11142025_Dip_Buyer_FCFYield11142025CRLCharles River Laboratories InternationalDip BuyDB | FCFY OPMDip Buy with High FCF Yield and High Margin
Buying dips for companies with high FCF yield and meaningfully high operating margin
4.1%4.1%-3.7%
GDRX_11142025_Dip_Buyer_High_CFO_Margins_ExInd_DE11142025GDRXGoodRxDip BuyDB | CFO/Rev | Low D/EDip Buy with High Cash Flow Margins
Buying dips for companies with significant cash flows from operations and reasonable debt / market cap
-9.8%-9.8%-11.8%
ASTH_11142025_Dip_Buyer_High_FCF_Yield_ExInd_DE_RevG11142025ASTHAstrana HealthDip BuyDB | FCF Yield | Low D/EDip Buy with High Free Cash Flow Yield
Buying dips for companies with significant free cash flow yield (FCF / Market Cap) and reasonable debt / market cap
6.0%6.0%-5.5%
SGRY_11142025_Dip_Buyer_High_FCF_Yield_ExInd_DE_RevG11142025SGRYSurgery PartnersDip BuyDB | FCF Yield | Low D/EDip Buy with High Free Cash Flow Yield
Buying dips for companies with significant free cash flow yield (FCF / Market Cap) and reasonable debt / market cap
9.7%9.7%-1.4%
TFX_11072025_Dip_Buyer_FCFYield11072025TFXTeleflexDip BuyDB | FCFY OPMDip Buy with High FCF Yield and High Margin
Buying dips for companies with high FCF yield and meaningfully high operating margin
6.2%6.2%-5.1%
Unique KeyDateTickerCompanyCategoryTrade Strategy6M Fwd Rtn12M Fwd Rtn12M Max DD
CRL_11142025_Dip_Buyer_FCFYield11142025CRLCharles River Laboratories InternationalDip BuyDB | FCFY OPMDip Buy with High FCF Yield and High Margin
Buying dips for companies with high FCF yield and meaningfully high operating margin
4.1%4.1%-3.7%
GDRX_11142025_Dip_Buyer_High_CFO_Margins_ExInd_DE11142025GDRXGoodRxDip BuyDB | CFO/Rev | Low D/EDip Buy with High Cash Flow Margins
Buying dips for companies with significant cash flows from operations and reasonable debt / market cap
-9.8%-9.8%-11.8%
ASTH_11142025_Dip_Buyer_High_FCF_Yield_ExInd_DE_RevG11142025ASTHAstrana HealthDip BuyDB | FCF Yield | Low D/EDip Buy with High Free Cash Flow Yield
Buying dips for companies with significant free cash flow yield (FCF / Market Cap) and reasonable debt / market cap
6.0%6.0%-5.5%
SGRY_11142025_Dip_Buyer_High_FCF_Yield_ExInd_DE_RevG11142025SGRYSurgery PartnersDip BuyDB | FCF Yield | Low D/EDip Buy with High Free Cash Flow Yield
Buying dips for companies with significant free cash flow yield (FCF / Market Cap) and reasonable debt / market cap
9.7%9.7%-1.4%
TFX_11072025_Dip_Buyer_FCFYield11072025TFXTeleflexDip BuyDB | FCFY OPMDip Buy with High FCF Yield and High Margin
Buying dips for companies with high FCF yield and meaningfully high operating margin
6.2%6.2%-5.1%

Recent Active Movers

Recent Active Movers

More From Trefis

Peer Comparisons for Korro Bio

Peers to compare with:

Financials

KRROVRTXAIXCALPSBBOTEVMNMedian
NameKorro BioVertex P.AIxCryptoALPS BridgeBi.Evommune  
Mkt Price6.04463.132.541.0711.0721.228.55
Mkt Cap0.1118.4----59.2
Rev LTM611,7230-0106
Op Inc LTM-99-92-5--93-70-92
FCF LTM-743,337-6--60-64-60
FCF 3Y Avg-2,064-10---1,027
CFO LTM-673,718-6--60-64-60
CFO 3Y Avg-2,419-10---1,204

Growth & Margins

KRROVRTXAIXCALPSBBOTEVMNMedian
NameKorro BioVertex P.AIxCryptoALPS BridgeBi.Evommune  
Rev Chg LTM-10.3%----10.3%
Rev Chg 3Y Avg-10.5%----10.5%
Rev Chg Q-11.0%----11.0%
QoQ Delta Rev Chg LTM30.3%2.7%----16.5%
Op Mgn LTM-1,569.1%-0.8%----700.7%-700.7%
Op Mgn 3Y Avg-26.2%----26.2%
QoQ Delta Op Mgn LTM411.4%1.0%----206.2%
CFO/Rev LTM-1,071.0%31.7%----635.6%-635.6%
CFO/Rev 3Y Avg-23.1%----23.1%
FCF/Rev LTM-1,175.9%28.5%----636.5%-636.5%
FCF/Rev 3Y Avg-19.8%----19.8%

Valuation

KRROVRTXAIXCALPSBBOTEVMNMedian
NameKorro BioVertex P.AIxCryptoALPS BridgeBi.Evommune  
Mkt Cap0.1118.4----59.2
P/S18.78.5----13.6
P/EBIT-1.222.4----10.6
P/E-1.327.2----13.0
P/CFO-1.726.9----12.6
Total Yield-77.9%3.7%-----37.1%
Dividend Yield0.0%0.0%----0.0%
FCF Yield 3Y Avg-2.3%----2.3%
D/E0.40.0----0.2
Net D/E-0.4-0.0-----0.2

Returns

KRROVRTXAIXCALPSBBOTEVMNMedian
NameKorro BioVertex P.AIxCryptoALPS BridgeBi.Evommune  
1M Rtn-83.6%8.7%---9.9%--9.9%
3M Rtn-76.8%16.8%--12.5%-12.5%
6M Rtn-49.2%3.9%-----22.6%
12M Rtn-87.3%1.3%-----43.0%
3Y Rtn174.5%44.1%----109.3%
1M Excs Rtn-83.6%8.7%---9.9%--9.9%
3M Excs Rtn-83.8%11.3%--4.5%-4.5%
6M Excs Rtn-63.9%-10.8%-----37.4%
12M Excs Rtn-101.9%-14.6%-----58.3%
3Y Excs Rtn114.8%-25.9%----44.5%

Financials

Price Behavior

Short Interest

Short Interest: As Of Date11142025
Short Interest: Shares Quantity1,441,185
Short Interest: % Change Since 1031202524.1%
Average Daily Volume1,452,423
Days-to-Cover Short Interest1
Basic Shares Quantity9,390,542
Short % of Basic Shares15.3%

SEC Filings

Expand for More

Report DateFiling DateFiling
6302025812202510-Q 6/30/2025
3312025507202510-Q 3/31/2025
12312024318202510-K 12/31/2024
93020241112202410-Q 9/30/2024
6302024813202410-Q 6/30/2024
3312024514202410-Q 3/31/2024
12312023326202410-K 12/31/2023
123120229212023S-4/A 12/31/2022