Financial Fragility in Societies of LLM Agents: Coordination Failures and Stabilizing Mechanisms
Authors: Zhenhao Fu, Ruipeng Xu, Qibing Ren
Organizations: Shanghai Advanced Institute of Finance, Shanghai Jiao Tong University · School of Artificial Intelligence, Shanghai Jiao Tong University
Individually protective decisions can produce avoidable collective failures. As large language model (LLM) agents take on greater roles in financial decision-making, financial AI safety must therefore be considered not only at the level of individual agents, but also at the level of the systems they jointly create. We study this problem with FRAIL, a controlled experimental framework that places LLM agents in three dynamic financial environments---bank runs, debt rollover, and reward crowdfunding---where agents' decisions reshape the financial conditions faced by others. Across seven leading LLMs, we find widespread collective fragility even when no agent is instructed to destabilize the system: 77% of baseline bank-run episodes and 83% of debt-rollover episodes end in failure. We then compare three interaction mechanisms based on compensated commitments, centralized commitment agreements, and participant-led coalitions. All three improve aggregate outcomes, but no single mechanism performs best across all financial structures. Across mechanisms, successful stabilization shares a common temporal pattern: broad commitment forms early, before defensive behavior becomes self-reinforcing. Our findings show that individually capable agents do not automatically form safe financial systems, highlighting system-level evaluation and interaction design as central problems for financial AI safety. Code is available at https://anonymous.4open.science/r/FinFrail-CF26.
Figures & tables
Figure 1: Overview of FRAIL. Agent decisions repeatedly update a shared financial state, producing fragile or stabilized trajectories, while interaction mechanisms can redirect these dynamics through credible commitments.
Figure 2: Three financial environments. Each panel shows one environment’s participants, their round-level choice, and the contrast between the coordinated outcome (green) and the failure outcome (red).
Condition
Bank run
Debt rollover
Reward crowdfunding
Commitment and exit
Visibility
M0
No agreement
No agreement
No agreement
Actions unrestricted
Aggregate financial state only
M1
Paid retention agreement
Paid rollover agreement
Paid pledge agreement
Binding; no unilateral exit
Selective disclosure by central player
M2
Deposit protection agreement
Standstill agreement
Letter of intent
Exit with one-round notice
Aggregate commitment; optional disclosure
M3
Depositor coalition
Creditor committee
Backer coalition
Exit with advance notice; no re-entry
Member information; coalition-voted disclosure
Table 1: Mechanism implementation across environments.
Environment
Mechanism
Average W
GPT-sol
GPT-terra
Claude-Sonnet
GLM
Qwen
DeepSeek
MiniMax
Bank run
M0: baseline
0.215 ± 0.139
0.000 (0/5)
0.000 (0/5)
0.000 (0/5)
0.000 (0/5)
0.174 (1/5)
1.000 (5/5)
0.333 (2/5)
M1: compensated
0.507 ± 0.156
0.000 (0/5)
0.381 (2/5) ↑
0.000 (0/5)
0.952 (5/5) ↑
0.488 (3/5) ↑
1.000 (5/5)
0.725 (4/5) ↑
M2: agreement
0.615 ± 0.147
0.090 (1/5) ↑
0.293 (2/5) ↑
0.239 (2/5) ↑
0.854 (5/5) ↑
0.956 (5/5) ↑
0.997 (5/5) ↓
0.879 (5/5) ↑
M3: coalition
0.737 ± 0.169
0.172 (1/5) ↑
0.000 (0/5)
0.988 (5/5) ↑
0.999 (5/5) ↑
1.000 (5/5) ↑
1.000 (5/5)
1.000 (5/5) ↑
Debt rollover
M0: baseline
0.168 ± 0.092
0.000 (0/5)
0.000 (0/5)
0.633 (3/5)
0.016 (0/5)
0.173 (1/5)
0.000 (0/5)
0.353 (2/5)
M1: compensated
0.514 ± 0.161
0.398 (2/5) ↑
0.000 (0/5)
0.994 (5/5) ↑
0.993 (5/5) ↑
0.416 (2/5) ↑
0.000 (0/5)
0.800 (4/5) ↑
Table 2: Welfare realization W under M0–M3.
Figure 3: Welfare realization under M0–M3. (a) Welfare realization by environment, averaged across the seven model means; error bars show the SE across model means. (b) Mechanism scorecard pooling environments, models, and episodes; larger values indicate stronger performance on each dimension. Dimension definitions are given in Appendix H.3 .
Figure 4: Round-by-round dynamics under M0–M3. Rows show three layers of the mechanisms’ action—financial trajectories (top), committed amounts (middle), and reported defensive intent (bottom; for crowdfunding, the share of episodes not yet launched); columns show the three environments. Lines report episode means. Measurement conventions are given in Appendix H.4 .
Appendix figures & tables12 assets
Supplementary material from the paper’s appendix.
Appendix
Figure 5: Architecture of the FRAIL simulation engine. Each round, the engine constructs an authorized view of the current financial state for every agent. Agents return structured decisions; the engine executes mechanism rules, samples realized actions, performs settlement, and updates information and the financial state. All execution is recorded in structured logs and per-round checkpoints for replay and analysis.
Game
Participants
Horizon
Core action
Outcome under full coordination
Success
Failure
Bank run
15 depositors; 1 bank
12
Stay or withdraw
Bank survives and pays everyone’s deposits with interest
Bank survives
Insolvency or liquidity failure
Debt rollover
8 creditors; 1 borrower
7
Redeem or roll
All claims met at maturity and no wasteful early liquidation
All claims met
Insolvency or liquidity default
Reward crowdfunding
15 investors; 1 founder
10
Pledge, wait, or withdraw
Immediate first-round launch
Project launches
No launch by the deadline
Appendix
Table 3: Overview of the three financial environments.
Bank run
Depositors
15 (unit deposit 1.000; total deposits 15.000)
Horizon
12 rounds
Initial cash / long-term assets
1.125 / 15.075
Deposit maturity yield
1.114 per unit
Asset maturity return / early-sale price
1.131 / 0.850 per unit
Processing capacity
up to 3.750 in withdrawals per round; excess requests expire
Appendix
Table 4: Game parameters in the stable regime.
Environment
Parameter
Expansion
Stable
Contraction
Bank run
Asset maturity return R
1.180
1.131
1.080
Initial cash L0
1.500
1.125
1.125
Early-sale price h
0.850
0.850
0.750
Debt rollover
Initial cash L0
0.500
0.200
0.000
Reward crowdfunding
Goal G
12.000
14.000
15.000
Reward v
1.250
1.150
1.100
Appendix
Table 5: Ablated parameters by regime.
Family
Model
Provider
Temperature
CoT
Thinking effort
Max tokens
GPT
gpt-5.6-sol
01tree relay
1.0
Yes
Default
8192
GPT
gpt-5.6-terra
01tree relay
1.0
Yes
Default
8192
Claude
claude-sonnet-5
01tree relay
1.0
Yes
Default
8192
GLM
glm-5.3-flash
Zhipu
1.0
Yes
Default
8192
Qwen
qwen3.8-flash
Alibaba Bailian
1.0
Yes
Default
8192
DeepSeek
deepseek-v4.1-flash
DeepSeek
1.0
Yes
Low*
8192
Appendix
Table 6: Model configurations. All models were accessed in September 2026.
Game
Call
When
Who is called
Bank run
Withdrawal decision
every round
all active depositors
Mechanism response
every round, M1–M3
all active depositors
Propose / publicize
every round, M1–M2
the bank
Debt rollover
Redeem-or-roll decision
maturity rounds
due creditors
Mechanism response
every round, M1–M3
targeted or committed creditors; joinable under M3
Propose / publicize
every round, M1–M2
the borrower
Appendix
Table 7: Call structure per round. “Due” creditors are those whose claim matures that round.
Game / Model
M0
M1
M2
M3
Bank run
GPT-sol
0.00 [0.00, 0.43]
0.00 [0.00, 0.43]
0.20 [0.04, 0.62]
0.20 [0.04, 0.62]
GPT-terra
0.00 [0.00, 0.43]
0.40 [0.12, 0.77]
0.40 [0.12, 0.77]
0.00 [0.00, 0.43]
Sonnet
0.00 [0.00, 0.43]
0.00 [0.00, 0.43]
0.40 [0.12, 0.77]
1.00 [0.57, 1.00]
GLM
0.00 [0.00, 0.43]
1.00 [0.57, 1.00]
1.00 [0.57, 1.00]
1.00 [0.57, 1.00]
Qwen 3.8
0.20 [0.04, 0.62]
0.60 [0.23, 0.88]
1.00 [0.57, 1.00]
1.00 [0.57, 1.00]
Appendix
Table 8: Success rates over five episodes per cell, with 95% Wilson score intervals in brackets, for the seven main model configurations in the stable regime.
Measure
M0: baseline
M1: compensated
M2: agreement
M3: coalition
Withdrawal rate (bank run)
0.536 ± 0.092
0.276 ± 0.076
0.301 ± 0.097
0.181 ± 0.112
Redemption rate (debt rollover)
0.382 ± 0.056
0.335 ± 0.045
0.180 ± 0.069
0.213 ± 0.041
First-launch round (crowdfunding)
3.392 ± 0.427
3.343 ± 0.565
1.833 ± 0.340
1.300 ± 0.191
Appendix
Table 9: Action-level measures by mechanism condition in the stable regime. Cells report the unweighted mean across the seven model means ± the standard error across model means. Withdrawal and redemption rates are shares of initial funding; first-launch round is averaged over episodes with a launch.
Figure 6: Early committed share and outcomes. Episodes are binned by the maximum committed share in rounds 1–3. Points are bin means with 95% confidence intervals; n is the number of episodes. Bank-run and debt-rollover panels report the success rate; the crowdfunding panel reports the launch round (10 marks no launch).
Environment
Mechanism
Expansion
Stable
Contraction
Bank run
M0: baseline
0.071 ± 0.049
0.044 ± 0.044
0.000 ± 0.000
M1: compensated
0.744 ± 0.218
0.455 ± 0.196
0.495 ± 0.286
M2: agreement
0.682 ± 0.230
0.586 ± 0.186
0.294 ± 0.233
M3: coalition
0.981 ± 0.010
0.747 ± 0.249
0.728 ± 0.108
Debt rollover
M0: baseline
0.148 ± 0.095
0.206 ± 0.148
0.064 ± 0.047
M1: compensated
0.723 ± 0.102
0.601 ± 0.242
0.298 ± 0.190
Appendix
Table 10: Welfare realization across economic regimes.
Environment
Mechanism
Average W
GPT-terra
Claude-Sonnet
GLM
Qwen
Bank run
M0: baseline
0.071 ± 0.049
0.000 (0/5)
0.074 (1/5)
0.000 (0/5)
0.209 (2/5)
M1: compensated
0.744 ± 0.218
1.000 (5/5) ↑
0.091 (1/5) ↑
0.913 (5/5) ↑
0.972 (5/5) ↑
M2: agreement
0.682 ± 0.230
1.000 (5/5) ↑
0.000 (0/5) ↓
0.827 (5/5) ↑
0.901 (5/5) ↑
M3: coalition
0.981 ± 0.010
0.972 (5/5) ↑
0.956 (5/5) ↑
0.997 (5/5) ↑
1.000 (5/5) ↑
Debt rollover
M0: baseline
0.148 ± 0.095
0.000 (0/5)
0.000 (0/5)
0.197 (1/5)
0.396 (2/5)
M1: compensated
0.723 ± 0.102
0.529 (3/5) ↑
0.623 (3/5) ↑
0.999 (5/5) ↑
0.743 (4/5) ↑
Appendix
Table 11: Welfare realization W in the expansion regime (four-model subset).
Environment
Mechanism
Average W
GPT-terra
Claude-Sonnet
GLM
Qwen
Bank run
M0: baseline
0.000 ± 0.000
0.000 (0/5)
0.000 (0/5)
0.000 (0/5)
0.000 (0/5)
M1: compensated
0.495 ± 0.286
0.979 (5/5) ↑
0.000 (0/5)
1.000 (5/5) ↑
0.000 (0/5)
M2: agreement
0.294 ± 0.233
0.979 (5/5) ↑
0.000 (0/5)
0.000 (0/5)
0.197 (1/5) ↑
M3: coalition
0.728 ± 0.108
0.531 (3/5) ↑
0.582 (3/5) ↑
0.800 (4/5) ↑
1.000 (5/5) ↑
Debt rollover
M0: baseline
0.064 ± 0.047
0.000 (0/5)
0.000 (0/5)
0.057 (0/5)
0.198 (1/5)
M1: compensated
0.298 ± 0.190
0.399 (2/5) ↑
0.000 (0/5)
0.794 (4/5) ↑
0.000 (0/5) ↓
Appendix
Table 12: Welfare realization W in the contraction regime (four-model subset).
Department of Electrical Engineering and Computer Science Massachusetts Institute of Technology · Sloan School of Management Massachusetts Institute of Technology · Belfer Center for Science and International Affairs Harvard Kennedy School