Portfolio Management Systems Agent Skill

Portfolio Management Systems

Core Concepts

> Expanded detail for each numbered section below lives in

> references/platform-details.md. Load it when the task needs:

> §1 the platform comparison table or IBOR/OBOR reconciliation dimensions; §2 full model

> specification, governance steps, or marketplace detail; §3 UMA cash-waterfall rules or the

> UMA/SMA/wrap comparison table; §4 drift measurement formulas, threshold configurations, or

> tax-aware rebalancing logic; §5 aggregation data sources and data-quality failure modes;

> §6 break-resolution workflow, corporate-action types, or cost basis methods; §8 daily vs.

> monthly calculation and benchmark tracking detail; §10 the custodian data-flow table,

> integration methods, and feed timing. (Reference §7 trading and §9 billing are pointers to

> the order-management-advisor and fee-billing skills — load those skills directly instead.)

1. Portfolio Management System Architecture

The PMS is the operational nerve center of an advisory practice, orchestrating data flow between custodians, trading platforms, reporting engines, CRM, and planning tools. Core functions include portfolio construction, model management, rebalancing, trading, performance reporting, and billing. Major platforms: Orion, Black Diamond, Tamarac, Addepar, Morningstar Direct, Advent/APX. The PMS serves as the firm's Investment Book of Record (IBOR), which must be reconciled daily against the custodian's Official Book of Record (OBOR).

2. Model Portfolio Management

Model portfolios define target allocations (asset classes, securities, weights) applied consistently across client accounts. Types include strategic (SAA), tactical (TAA overlays), and specialty models (income, ESG, tax-managed). Firms typically use a two-tier hierarchy (firm-level + advisor-customized). Model changes trigger versioning, account identification, trade proposal generation, and tax-aware transition. Third-party model marketplaces (BlackRock, DFA, Vanguard, PIMCO) allow smaller firms to access institutional-quality investment management.

3. Sleeve-Based and UMA Architecture

Unified Managed Accounts (UMAs) divide a single custodial account into virtual sub-accounts (sleeves), each following its own strategy or manager. Benefits: cross-sleeve tax optimization, simplified reporting, reduced account proliferation, and unified cash management. Cash waterfall rules govern deposits, withdrawals, and income allocation across sleeves. UMAs differ from SMAs (single-strategy, one manager) and mutual fund wraps (indirect ownership, limited customization). Typical minimums: $250K-$1M+.

4. Drift Monitoring and Rebalancing

Drift is the divergence of actual weights from targets caused by differential returns and cash flows. Measured as absolute drift (percentage-point difference) or relative drift (percentage of target). Threshold configurations range from conservative (3%/15%) to permissive (7%/30%). Rebalancing approaches: calendar-based, threshold-based, opportunistic (cash-flow-directed), and hybrid. Tax-aware rebalancing incorporates capital gains minimization, loss harvesting, wash sale avoidance, and gain budgets.

5. Held-Away Asset Aggregation

A complete client picture requires visibility into all assets, including employer plans, stock options, RSUs, bank accounts, and accounts at other custodians. Data sources: aggregation services (Plaid, Yodlee, MX, ByAllAccounts), custodian feeds, manual entry, and employer plan integrations. Challenges include data staleness, categorization errors, and broken connections. The PMS should provide both managed-only and total-household reporting views.

6. Portfolio Accounting and Reconciliation

Portfolio accounting tracks positions, transactions, cost basis, cash flows, and accrued income. Daily reconciliation compares PMS against custodian across three dimensions: positions, transactions, and cash. Breaks require classification, root-cause diagnosis, correction, and documentation. Common break sources: corporate actions (splits, mergers, spin-offs, DRIP), trade settlement timing, and data feed issues. Cost basis methods: specific identification, FIFO, and average cost.

7. Trading and Order Management Integration

The PMS generates trade proposals from model changes, rebalancing triggers, cash flows, and ad-hoc instructions. In larger firms, trades flow through a separate OMS for compliance checks, block aggregation, and execution routing. Block trading aggregates orders across accounts for best execution with pro-rata allocation. Pre-trade checks cover restricted securities, concentration limits, client restrictions, regulatory limits, and cash minimums. Implementation methods: direct custodian trading, third-party EMS, and mutual fund trading platforms.

8. Performance Calculation Engine

The PMS computes returns at multiple levels: security, sleeve, account, household, model, composite, and firm. TWR (time-weighted) eliminates cash flow impact for manager evaluation and GIPS compliance. MWR (money-weighted/IRR) reflects the investor's actual experience. Daily performance provides the most precise TWR; monthly uses approximations like Modified Dietz. Benchmarks (primary, blended, custom) must be tracked at the same frequency as portfolio returns.

9. Billing and Fee Calculation

Fee structures: AUM-based (flat or tiered/breakpoint), flat/retainer, performance-based (qualified clients only), and blended. Billing frequency: quarterly (most common), monthly, or annual. Advance billing requires proration; arrears billing delays revenue recognition. Billable AUM determination requires clear policies on included/excluded assets and household aggregation. Fee deduction via direct debit (most common) or invoice. Revenue tracking covers client, advisor, model, and strategy dimensions.

10. Custodian Integration and Data Feeds

Custodian integration provides the data backbone: positions, transactions, cash, cost basis, corporate actions, and new accounts flow from custodian to PMS; trade instructions and fee invoices flow from PMS to custodian. Integration methods: proprietary batch feeds (CSV/XML), FIX protocol, APIs, and third-party aggregators. Feed timing: EOD batch (most common), intraday updates, and real-time streaming. Multi-custodian management requires data normalization, consolidated views, custodian-specific trade routing, and separate reconciliation. Custodian transitions (e.g., TD Ameritrade to Schwab) require account mapping, feed migration, and historical data transfer.

Worked Examples

See references/examples.md for three end-to-end worked examples —

a PMS migration for a growing RIA, a UMA/sleeve implementation for HNW clients, and a

reconciliation break investigation. Load it when the user needs a full scenario walkthrough.

Common Pitfalls

• Treating the PMS as the official record. The custodian, not the PMS,

maintains the legally authoritative record of client assets. When discrepancies

exist, the custodian record governs. Firms that rely solely on PMS data without

reconciliation risk reporting incorrect positions and performance.

• Neglecting daily reconciliation. Firms that reconcile weekly or monthly

allow breaks to compound, making root-cause diagnosis much harder. A corporate

action missed on Monday may cause cascading errors in performance, billing,

and rebalancing throughout the week.

• Over-engineering drift thresholds. Setting drift bands too tight (e.g., 1%

absolute) generates excessive trading, increasing costs and tax drag. Setting

bands too loose (e.g., 10% absolute) allows portfolios to deviate significantly

from the intended risk profile. Calibrate thresholds based on asset class

volatility and client tax sensitivity.

• Ignoring wash sale rules across accounts. Tax-loss harvesting in one account

while purchasing substantially identical securities in another account with the

same tax ID disallows the loss. The PMS must monitor wash sale windows across

all accounts for a client or household.

• Stale held-away data. Aggregated held-away data that has not refreshed in

weeks or months can lead to materially incorrect total-household allocation views

and flawed planning recommendations. Implement alerts for stale connections and

establish a process for client re-authentication.

• Inconsistent model governance. Allowing advisors to freely modify firm models

without oversight creates style drift and compliance risk. Establish clear

policies on which model elements advisors can customize and require documentation

of deviations.

• Cost basis discrepancies between PMS and custodian. The PMS and custodian may

calculate cost basis differently, especially after corporate actions, transfers,

or wash sale adjustments. If the firm relies on PMS cost basis for tax-loss

harvesting decisions but the custodian reports different basis to the IRS

(Form 1099-B), clients may face unexpected tax consequences.

• Billing on stale or unreconciled data. Calculating fees on PMS positions that

have not been reconciled against the custodian may result in over- or under-billing.

Always reconcile before running billing.

• Failing to test custodian feed changes. Custodians periodically update their

data feed formats. Firms that do not monitor for format changes or test in a

staging environment before production risk silent data-import failures.

10. Overlooking performance calculation methodology. Reporting MWR when TWR

is appropriate (or vice versa) can mislead clients or violate GIPS standards.

Understand when each methodology is appropriate and clearly label which method

is used in client-facing reports.

Cross-References

• asset-allocation (wealth-management plugin) — PMS implements the strategic

and tactical asset allocation defined in the client's investment policy. Model

portfolios in the PMS are the operational expression of asset allocation decisions.

• rebalancing (wealth-management plugin) — The PMS rebalancing engine applies

rebalancing theory (threshold-based, calendar-based, opportunistic) to live client

portfolios. The rebalancing skill defines the theory; this skill covers the

system implementation.

• tax-efficiency (wealth-management plugin) — PMS tax-loss harvesting,

wash sale monitoring, and tax-aware rebalancing apply the tax-efficiency

principles defined in the tax-efficiency skill to operational workflows.

• performance-metrics (wealth-management plugin) — The PMS calculates the

return metrics (TWR, MWR, alpha, Sharpe ratio) defined in the performance-metrics

skill. That skill defines the math; this skill covers how the PMS implements the

calculations.

• performance-reporting (wealth-management plugin) — The PMS generates the

underlying performance data that feeds client-facing performance reports. The

reporting skill covers presentation and communication; this skill covers

calculation and data infrastructure.

• gips-compliance (compliance plugin) — PMS composite construction and

performance calculation must satisfy GIPS requirements for firms that claim

compliance. The GIPS skill defines the standards; this skill covers the PMS

configuration needed to meet them.

• order-management-advisor (advisory-practice plugin) — The OMS receives

trade lists generated by the PMS. This skill covers trade list generation; the

OMS skill covers order routing, execution, and allocation.

• financial-planning-integration (advisory-practice plugin) — The PMS

current portfolio (including held-away aggregation) feeds financial planning

tools for projections and scenario analysis.

• fee-billing (advisory-practice plugin) — The PMS fee engine handles

billing calculations described here. The fee-billing skill covers the broader

billing operations workflow including invoicing, collections, and revenue

recognition.

• client-reporting-delivery (advisory-practice plugin) — PMS performance

data, portfolio holdings, and asset allocation feeds the client reporting and

delivery workflow.