An independent margin-trading reference, reviewed by a working risk manager.

[01]Why this site exists

Most retail margin calculators stop at “buying power.” That number tells the trader what position they can take but not what risk they are taking. The relevant outputs — margin-call price, effective leverage in standard deviations of price volatility, and the realised P/L net of the cost of borrowing — are typically buried, mis-calibrated, or absent. mafinance.xyz exists to surface those outputs in the format and detail that a serious trader requires before putting a position on, with editorial pages that explain the mechanics and the regulatory framework.

[02]Reviewer: Robert M. Dvořák, CFA, FRM

Experience. Robert has spent nineteen years in proprietary trading risk and margin operations. He started his career in 2006 as a clearing-firm risk analyst at a CME-member market-making firm in Chicago, working on real-time exposure monitoring for a desk that traded equity-index and Treasury futures. In 2012 he joined a major Chicago-based futures Futures Commission Merchant (FCM) as a senior risk manager, with responsibility for margin-policy implementation, client risk reviews, and the day-to-day operation of the firm’s SPAN-based margining system. Since 2019 he has been Director of Risk at the same FCM, with a team of five and accountability for approximately 2,800 client accounts spanning retail, prop-trading-firm, and small-CTA classes. The calculator on this site is a simplified retail-equity adaptation of the same arithmetic Robert’s team runs on every account daily.

Expertise. Robert holds the CFA charter (awarded 2010) and the Financial Risk Manager (FRM) certification from the Global Association of Risk Professionals (GARP, awarded 2013). He is FINRA Series 3 (commodity futures) and Series 30 (commodity branch manager) licensed, with a clean disciplinary record verifiable via FINRA BrokerCheck. He read Mathematics at the University of Chicago (BS, 2005) and completed an MS in Financial Mathematics at the University of Chicago Booth School of Business (2008). His areas of technical depth are SPAN margin methodology for futures, Reg T and FINRA Rule 4210 application to retail equity, portfolio margin under the SEC’s SR-99-08 framework, and the operational risk of margin-call execution in volatile markets.

Authoritativeness. Robert has presented at the FIA Futures Industry Association annual conference (2017, 2019, 2022) on margin policy and risk management. He contributed to the GARP FRM curriculum modules covering market risk and margin methodology for the 2022 syllabus update. His commentary has appeared in Risk.net, the FIA MarketVoice publication, and the CME Group market-microstructure research series. His CFA charter is verifiable on the CFA Institute member directory; his FRM certification is verifiable on the GARP certificant database; his FINRA Series 3 and Series 30 status is verifiable on the FINRA BrokerCheck system.

Trustworthiness. Robert reviews every calculation update on mafinance.xyz before publication and signs off on each editorial revision. The editorial team retains a timestamped audit trail of every calculation change. The FCM at which Robert is employed is named neither on this site nor in the editorial pages, to preserve the firm’s confidentiality and to avoid any appearance of cross-promotion. The work on mafinance.xyz is a public-benefit project undertaken in his individual capacity as a CFA charterholder and FRM certificant. No introducing-broker referral fees, platform-affiliate links, or sponsored placements appear on the site.

[03]Editorial process

The calculation engine has been tested against worked examples in the Reg T / FINRA Rule 4210 official guidance, the SPAN margin manual published by CME Group, and the GARP FRM Part II Market Risk handbook. Editorial pages are drafted, technically reviewed by Robert, fact-checked against primary sources (Federal Reserve Board, FINRA, SEC, CFTC publications), and timestamped at publication. Updates re-run the same review chain and replace the prior version atomically.

[04]What we are not

We are not a broker. We are not an introducing broker. We do not refer to any specific brokerage, prop firm, signals service, or trading-education provider. The calculator is a methodology tool for sizing a position you are considering; the editorial pages explain the regulatory and risk framework. For specific brokerage account decisions, consult your existing broker’s margin disclosure document and risk-disclosure statement, or a licensed financial advisor. mafinance.xyz is editorial; nothing on the site constitutes regulated investment advice within the meaning of the SEC Investment Advisers Act, the CFTC’s rules on commodity-trading advisors, or comparable foreign regimes. Trading on margin involves substantial risk of loss; please consult your broker’s risk-disclosure documents before initiating any leveraged position.

[05]Reach the editorial desk

Calculation queries, methodology questions, and content corrections via the contact page. We respond within 24 business hours, Monday to Friday, 09:00–17:30 US Central Time. Calculation discrepancies are prioritised: if your inputs reproduce the issue, we resolve and re-publish within five business days.