AMIB Operador de Bolsa common mistakes
AMIB Operador de Bolsa · Understand the traps and how to avoid them.
Treating the CNBV, Banxico, and the Bolsa Mexicana de Valores as interchangeable authorities, so the candidate attributes rulemaking, sanctioning, or listing decisions to the wrong body.
Study notes summarize 'the regulator' generically, and the candidate memorizes obligations without anchoring each one to the legal instrument and the institution that issues it.
What to do instead
Build a one-page authority map: CNBV (prudential conduct and disclosure under the Ley del Mercado de Valores), Banxico (monetary, payment systems, FX), SHCP (financial-sector policy), BMV/BIVA (exchange listing and operating rules). For every rule you memorize, write the issuing authority next to it and self-quiz by authority rather than by rule.
Confusing the corporate actions that change share count and price mechanically (split, reverse split, stock dividend) with those that transfer value between parties (cash dividend), and mis-stating the ex-date price adjustment for each.
All are filed under 'corporate events' and candidates memorize definitions without practicing the arithmetic of the price and share-count adjustment on a worked example.
What to do instead
Drill a table with columns: event, shares outstanding change, price adjustment, shareholder wealth change, tax treatment. Solve at least five numeric scenarios per event type (e.g., a 2-for-1 split on a MXN 100 share, a 10% stock dividend, a MXN 3 cash dividend ex-date drop) until the adjustment is automatic.
Quoting a bond's yield without specifying the convention, and mixing nominal, current, yield-to-maturity, and yield-to-worst figures as if they were comparable, or pricing a Mexican fixed-rate bond using a US-style day count.
Candidates learn 'yield' as a single concept and only see clean textbook examples; the Mexican market's conventions (e.g., actual/360 for many money-market instruments, clean vs. dirty price, ISR withholding on interest) are learned late or not at all.
What to do instead
Always label the yield type and the day-count and compounding convention in your scratch work. Practice converting between clean and dirty price, computing accrued interest, and reconciling YTM with yield-to-worst on a callable bond. Do at least one full bond pricing exercise per convention tested.
Valuing an option or structured note with intuition about direction ('the stock will rise, so the note is worth more') instead of applying no-arbitrage pricing, and ignoring that a structured product is a bond plus an embedded derivative whose value decomposes.
Derivatives are often studied qualitatively, and candidates under-prepare for payoff-diagram and replication questions that require decomposition rather than opinion.
What to do instead
For every structured product, write the payoff function, decompose it into a zero-coupon bond plus option legs, and sketch the payoff diagram at maturity. Practice replication and put-call parity numerically so that pricing follows from no-arbitrage, not from a market view.
Running a DCF by picking a discount rate and terminal growth from memory without tying the rate to the cash-flow definition (FCFF vs. FCFE, nominal vs. real, MXN vs. USD) or checking that terminal growth is below the long-run nominal growth of the economy.
Candidates memorize the DCF formula but not the consistency conditions; exam items with mismatched cash flow and discount rate are designed to catch exactly this.
What to do instead
Before computing, state four consistency checks: cash-flow definition matches the discount rate (WACC for FCFF, cost of equity for FCFE), currency matches, nominal/real matches, and terminal growth is below the risk-free or nominal GDP growth. Build a checklist you apply to every valuation question.
Reading a technical signal (e.g., a moving-average crossover or RSI level) as a standalone buy or sell recommendation, without specifying the timeframe, the confirmation rule, or the invalidation level that defines the trade's risk.
Candidates memorize indicator definitions and thresholds but never practice turning an indicator into a complete, falsifiable trade plan with entry, stop, and target.
What to do instead
For each indicator, write a full trade specification: timeframe, entry trigger, confirmation, invalidation/stop, target, and position size. Backtest the rule on a small sample of historical prices and record the win rate and payoff so you understand the signal's conditional nature rather than treating it as deterministic.
Computing a portfolio's expected return and risk with arithmetic averages and simple weighted sums while ignoring correlations, and then recommending an allocation without checking it against the investor's IPS constraints (horizon, liquidity, legal limits).
Candidates default to single-asset intuition and skip the covariance term; the IPS is read as boilerplate rather than as binding constraints on the recommendation.
What to do instead
Always compute portfolio variance with the covariance/correlation term and show the diversification effect numerically. Before answering an allocation question, extract the IPS constraints (return objective, risk tolerance, liquidity, time horizon, legal/regulatory limits) into a checklist and verify the proposed portfolio against each one.
Reporting VaR as the maximum possible loss, or comparing VaR figures computed at different confidence levels, horizons, or methodologies, and omitting stress testing and liquidity assumptions entirely.
VaR is taught as a single headline number, and the confidence level, horizon, and distributional assumptions are treated as footnotes rather than as part of the definition.
What to do instead
State every VaR figure as a full sentence: confidence level, horizon, methodology, and currency. Memorize that VaR is a threshold loss not exceeded with a given probability, and that it says nothing about the tail beyond it. Pair every VaR answer with a stress-test or expected-shortfall complement and note liquidity assumptions.
Handling a conflict-of-interest or material non-public information scenario by choosing the option that maximizes client outcome or firm revenue, rather than the option that satisfies the duty of confidentiality and the disclosure/abstention rules.
Candidates reason from commercial instinct and from a general 'act in the client's best interest' slogan, without mapping the scenario to the specific standard (fiduciary duty, MNPI abstention, disclosure of conflicts, suitability).
What to do instead
For each ethics scenario, identify the duty at stake (loyalty, confidentiality, disclosure, suitability, market integrity), then apply the rule mechanically: if MNPI, do not trade or tip and escalate; if a conflict, disclose and manage or decline. Practice with written rationales that cite the specific duty rather than the outcome.
Confusing the trade date with the settlement date, mis-stating the T+ settlement cycle, or overlooking the funding and fails consequences when answering a post-trade question.
Operational detail is treated as back-office trivia, so candidates skim the settlement section and cannot trace the cash and securities legs through the clearing and settlement process.
What to do instead
Draw the full post-trade flow (execution, confirmation, clearing, settlement, custody) for an equity trade and a bond trade, labeling the trade date, settlement date, and the funding obligation on each leg. Practice 'what happens if the buyer fails to deliver cash on settlement date' scenarios to internalize the consequences.