Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The demise of constant price impact functions and single-time step
  models of speculation   Constant and symmetric price impact functions, most commonly used in
agent-based market modelling, are shown to give rise to paradoxical and
inconsistent outcomes in the simplest case of arbitrage exploitation when
open-hold-close actions are considered. The solution of the paradox lies in the
non-constant nature of real-life price impact functions. A simple model that
includes explicit position opening, holding, and closing is briefly introduced
and its information ecology discussed, shedding new light on the relevance of
the Minority Game to the study of financial markets.

25
The categories of this paper are: patt-sol
11
The categories of this paper are: hep-lat
20
The categories of this paper are: acc-phys
37
The categories of this paper are: supr-con
36
The categories of this paper are: cmp-lg
24
The categories of this paper are: dg-ga
34
The categories of this paper are: chem-ph
12
The categories of this paper are: nucl-th
33
The categories of this paper are: plasm-ph
21
The categories of this paper are: adap-org
10
The categories of this paper are: q-bio
27
The categories of this paper are: comp-gas
35
The categories of this paper are: mtrl-th
14
The categories of this paper are: math-ph
5
The categories of this paper are: gr-qc
28
The categories of this paper are: alg-geom