László Siller

Laszlo advises boards and senior management on valuation, financial management and decision critical modelling. His work combines financial analysis with decision science so that pricing, risk and capital allocation remain coherent as evidence changes. He delivers audit ready documentation that can withstand regulatory review and external scrutiny.

Since 2015 Laszlo has worked as an independent advisor on valuation, long horizon forecasting, model validation and financial reporting refinement. Since 2022 he has supported Deloitte in Central Europe in a senior manager capacity on energy modelling, risk and compliance frameworks and regulator facing documentation, with alignment to prevailing market rules and internal control expectations. His independent practice is centred on valuation and strategy for energy, infrastructure and resource intensive businesses, with projects that link analytical design to leadership decisions.

Prior to independent practice Laszlo held risk and quantitative roles across the European energy market. He served as Risk Officer at RWE in Germany and Hungary from 2013 to 2017 with responsibility for portfolio risk assessment, daily performance reporting and limit supervision. Between 2009 and 2012 he worked in quantitative and market analysis roles at regional trading firms where he developed pricing and hedging models, time series methods and stress testing routines. He began his career in capital markets where he learned market microstructure, price formation and liquidity dynamics. These early experiences continue to inform the practical design of decision tools that can be explained and defended in a board setting.

Laszlo’s portfolio spans power and renewables, gas and LNG, industrial supply chains and data driven service businesses. Representative corporate exposure includes EON, RWE, PETRONAS, Iberdrola, ENEL Global, CEZ, Tinmar, General Electric and Societe Generale. In addition to delivery work he provides executive briefings and capability building programs that help management teams establish consistent standards for forecasting, pricing and strategic reporting across Europe and the MENA region.

The practice integrates historical backcasting, real time sensitivity analysis and long horizon scenario work. Models remain small enough to explain, with a clear separation between what is known, what is estimated and what is assumed. Signals that justify action are defined in advance and ownership of updates is explicit. Documentation is prepared to a standard suitable for audit, regulator review and internal governance. The approach is designed to preserve optionality until uncertainty falls while keeping delivery on schedule.

Recent work includes independent valuation assignments for assets and projects, price benchmark creation with supporting methodology, model validation for executive and audit committees, and the redesign of management reporting where boards require clear linkage from assumptions to outcomes. The outputs include executive ready memoranda, decision notes, validation records and implementation playbooks that can be reviewed and reconciled as conditions change.

Laszlo designs and delivers training that begins with leadership briefings and continues with practical coaching for operational teams. Themes include pricing and valuation under uncertainty, counterparty credit limits and collateral, supply chain optimisation, AI supported analytics and the design of governance and reporting processes. Programs are delivered on site, online or in hybrid format and are evaluated on clarity, relevance and measurable improvements in decision consistency.

Recent pieces include The Strategic Architecture of Modern Data Centers, The Future of Data Center Capacity and AI Fine Tuning in Enterprise along with further articles in Siller Strategic Insights. Writing is focused on topics where incentives, constraints and second order effects are under analysed. Publication is non promotional and independent, with a free public archive.

Laszlo studied international economics at Edutus University. His professional development includes training in risk management, derivatives, portfolio optimisation, corporate finance and applied machine learning. He holds a real estate valuation examination and a securities trader qualification. Working languages are Hungarian and English with operational German.

Work is delivered primarily in Python with common analytical libraries and in Excel for transparency where appropriate. Documentation and version control processes are maintained to preserve a full audit trail. Visualisation and presentation materials are prepared for board review in a style suitable for regulatory and external stakeholders.

Siller Business and Management Consulting provides advisory services. Legal services and representation are delivered by partner law firms. Where an assignment requires a formal legal opinion, licensed counsel is engaged and clearly identified. For authority specific valuation such as tax or hedge accounting a qualified local expert is involved as required.

Primary profile
https://siller.gmbh/laszlo-siller

Publications and archive
https://sillerconsulting.substack.com

Contact
laszlo@siller.gmbh

This page is provided for informational purposes. It does not constitute legal, investment or compliance advice. While believed to be accurate at the time of publication Siller Business and Management Consulting makes no representation as to completeness and disclaims liability arising from its use.

All publications authored by László Siller reflect his independent professional opinion. They do not represent the views of any client, partner, employer, or third party, and they should not be attributed to any organisation with which he collaborates.