"The test of a first-rate intelligence is the ability to hold two opposed ideas in mind at the same time and still retain the ability to function." — F. Scott Fitzgerald
One holding. Two views: what the market says it's worth, what you paid for it.
The Cost Basis Problem
Your accumulating ETF pays a dividend. No cash moves. But your cost basis just changed, and that affects CGT when you eventually sell.
Most systems track positions. Few track the tax-relevant history of how those positions evolved. When it's time to calculate gains, you're reconstructing from trade confirmations and corporate action notices.
Phantom Events
Stock splits, accumulating dividends, corporate actions. Something happened, nothing moved, but the tax treatment changed.
Two Truths, One Position
Market value says £10,000. Cost basis says £8,500. Both are correct. Most ledgers can only hold one.
Record
Every event, even when nothing moves
A dividend reinvestment on an accumulating ETF isn't a trade. But it's still an event that changes your tax position.
Meridian records the event with full metadata - what happened, when, why. The position may not change, but the audit trail captures the moment your cost basis adjusted.
Traditional Approach
- Trade executes → Position updates
- Corporate action → Manual adjustment
- No cash = No record
- CGT calculation = Spreadsheet
Meridian Approach
- Event recorded → All views update
- Corporate action → Automatic lineage
- No cash = Still recorded
- CGT calculation = Query
Value
Market value and cost basis from one source
Your client wants to know their portfolio value. HMRC wants to know their cost basis. Your performance team wants time-weighted returns. Same positions, different numbers.
One event creates multiple accounting views. Market valuation, cost basis, performance attribution - all derived from the same underlying positions, all consistent, all auditable.
sequenceDiagram
participant Corp as Corporate Action
box Meridian
participant Ledger as Ledger
participant Data as Market Data
participant Market as Market Value
participant Cost as Cost Basis
end
Corp->>Ledger: Accumulating dividend
Ledger->>Cost: Adjusted (now £8,200)
Note over Market: No change
Data->>Ledger: Price change
Ledger->>Market: Revalued (now £10,400)
Note over Cost: No change
What you could query: Position with Tax View
| Holding | Units | Market Value | Cost Basis | Unrealised Gain | Events |
|---|---|---|---|---|---|
| Vanguard FTSE Global | 450 | £12,400 | £9,800 | £2,600 | 3 adjustments |
| iShares Core MSCI World | 280 | £8,900 | £8,900 | £0 | - |
| L&G UK Index | 1,200 | £15,600 | £18,200 | -£2,600 | 1 adjustment |
| Total | £36,900 | £36,900 | £0 |
Click "3 adjustments" to see the dividend reinvestments that changed cost basis without cash movement.
Prove
What you knew, when you knew it
HMRC queries your client's 2022 disposal. What was the cost basis on that date? Which corporate actions affected it? Can you prove it?
Bi-temporal audit trail. Every position, every valuation, every adjustment - queryable as it was at any point in time. Not reconstructed. Retrieved.
What you could query: Cost Basis History
| Date | Event | Units | Cost Basis | Change |
|---|---|---|---|---|
| 2023-01-15 | Purchase | 400 | £8,000 | +£8,000 |
| 2023-04-01 | Accumulating dividend | 400 | £8,320 | +£320 |
| 2023-07-01 | Accumulating dividend | 400 | £8,660 | +£340 |
| 2023-09-20 | Purchase | 450 | £9,800 | +£1,140 |
| 2023-10-01 | Accumulating dividend | 450 | £10,150 | +£350 |
"What was the cost basis on 2023-08-15?" - £8,660. One query, full audit trail.
Performance That Adds Up
Time-weighted returns. Money-weighted returns. Attribution analysis. They all need the same clean position history.
When every cash flow and corporate action is recorded with precise timing, performance calculations become deterministic. Same inputs, same outputs, every time.
Time-Weighted Return
Daily positions, daily valuations. Geometric linking without manual intervention.
Money-Weighted Return
Every cash flow timestamped. IRR calculations from position history, not spreadsheets.
Attribution
Sector, asset class, manager. Slice performance by any dimension in the position metadata.
Benchmarking
Same valuation engine for portfolio and benchmark. Apples to apples.
The Engine
Settlement, corporate actions, valuations, reporting. Different systems, different truths.
Meridian is a backend ledger engine. One source of truth for positions. Your trading system writes. Your reporting system reads. The numbers match.
Event-Driven
Trades, corporate actions, valuations. All events, all recorded.
Bi-Temporal
What you knew when. Full audit trail for regulators.
Multi-View
Market value, cost basis, performance. Same position, different lenses.