Price manipulation in nonlinear transient impact models: rigidity before memory and complete positivity after memory

By Minhyeok Lee

Rating

1738
Battle Count: 69

Relevance

10/10
This paper directly addresses the fundamental question of whether empirically observed market impact models (square-root impact with power-law decay) are consistent with no-arbitrage/no-manipulation conditions. It resolves a long-standing open problem since Gatheral (2010) and provides concrete guidance for model architecture: concavity must be applied after memory (state-outside), not before (rate-inside), to avoid manipulation. The results have immediate implications for algorithmic execution, market impact modeling, and trading system design. All calibrated empirical exponent pairs lie in the manipulable set for the rate-inside architecture.

Implementation Complexity

9/10
The paper is a pure mathematics/theoretical finance paper requiring deep expertise in functional analysis, Volterra integral equations, dynamical systems, convex optimization, and market microstructure. The proofs involve chattering controls, resolvent theory, Bregman divergences, Stieltjes measures, finite isotone cones, and Bellman equations. While the results are directly applicable to model design, implementing the classification tests (e.g., complete positivity verification, Prony kernel residue tests, cut program feasibility) requires significant mathematical sophistication. The computational verification is straightforward but the theoretical framework is highly advanced.

Reproducibility

4/5
The paper includes a computational supplement (Appendix F) with Python sources using SymPy and mpmath for verifying transform algebra, evaluating finite strategies in interval arithmetic, and computing decimal values of analytically defined constants. All universal implications are proved analytically. The supplement is distributed as ancillary material with the arXiv version. However, the paper is primarily theoretical with no empirical data or trained models to reproduce. The AI-assisted research disclosure (Section 11) notes substantive assistance from generative AI systems.

About this paper

Methodology: Analytical classification and constructive proof. Problem types: Algorithmic Execution, Market Making, Risk Management, Optimization.

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