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    <journal-meta>
      <journal-id journal-id-type="nlm-ta">Rea Press</journal-id>
      <journal-id journal-id-type="publisher-id">null</journal-id>
      <journal-title>Rea Press</journal-title><issn pub-type="ppub">3009-4461</issn><issn pub-type="epub">3009-4461</issn><publisher>
      	<publisher-name>Rea Press</publisher-name>
      </publisher>
    </journal-meta>
    <article-meta>
      <article-id pub-id-type="doi">https://doi.org/10.22105/tqfb.v3i2.65</article-id>
      <article-categories>
        <subj-group subj-group-type="heading">
          <subject>Research Article</subject>
        </subj-group>
        <subj-group><subject>Non-stationary systems, Causal observables, Financial market dynamics, Regime transitions, Walk-forward selection, Decision functionals</subject></subj-group>
      </article-categories>
      <title-group>
        <article-title>Performance-Driven Causal Signal Engineering for  Financial Markets under Non-Stationarity</article-title><subtitle>Performance-Driven Causal Signal Engineering for  Financial Markets under Non-Stationarity</subtitle></title-group>
      <contrib-group><contrib contrib-type="author">
	<name name-style="western">
	<surname>Souza </surname>
		<given-names>Lucas A.</given-names>
	</name>
	<aff>Independent Researcher, Divinopolis, MG 35500-173, Brazil.</aff>
	</contrib></contrib-group>		
      <pub-date pub-type="ppub">
        <month>04</month>
        <year>2026</year>
      </pub-date>
      <pub-date pub-type="epub">
        <day>06</day>
        <month>04</month>
        <year>2026</year>
      </pub-date>
      <volume>3</volume>
      <issue>2</issue>
      <permissions>
        <copyright-statement>© 2026 Rea Press</copyright-statement>
        <copyright-year>2026</copyright-year>
        <license license-type="open-access" xlink:href="http://creativecommons.org/licenses/by/2.5/"><p>This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.</p></license>
      </permissions>
      <related-article related-article-type="companion" vol="2" page="e235" id="RA1" ext-link-type="pmc">
			<article-title>Performance-Driven Causal Signal Engineering for  Financial Markets under Non-Stationarity</article-title>
      </related-article>
	  <abstract abstract-type="toc">
		<p>
			We introduce a performance-driven framework for constructing strictly causal forward-oriented observables in strongly non-stationary time series. The method combines a robustly normalized composite of heterogeneous indicators with a causally computed derivative component, yielding a local phase-leading effect that is amplified near regime transitions while remaining fully causal. A hysteresis-based decision functional maps the observable into discrete system states, with execution delayed by one step to preserve strict temporal ordering. Adaptation is achieved through a walk-forward scheme, in which model parameters are selected using rolling train–validation windows and subsequently applied out-of-sample. In this setting, the validation segment acts as an internal performance screen rather than as a statistical validation set, and no claims of generalization are inferred from it alone. The framework is evaluated on high-frequency financial time series as an experimentally accessible realization of a non-stationary complex system. Under a controlled zero-cost setting, the resulting dynamics exhibit a pronounced risk-reshaping effect, characterized by smoother trajectories and reduced drawdowns relative to direct exposure, and should be interpreted as an upper bound on achievable performance. These results illustrate how causal signal engineering can generate anticipatory structure in non-stationary systems without relying on non-causal information, explicit horizon labeling, or high-capacity predictive models.
		</p>
		</abstract>
    </article-meta>
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