Help & Documentation
Learn how CerbyFi scores stocks and ETFs, how to use the watchlist and portfolios, and how the portfolio optimizer works.
How scoring works
CerbyFi scores every stock or ETF on a 100-point scale. The score is split across multiple categories. Each category contains individual metrics. Every metric is evaluated against thresholds and assigned a score from 0 to its maximum. Category scores are summed to produce the total.
Stock categories
Stocks are evaluated across five categories worth 20 points each:
| Category | Points | What it measures |
|---|---|---|
| Valuation | 20 | P/E, P/B, P/S, EV/EBITDA — is the stock priced reasonably? |
| Profitability | 20 | Net margin, ROE, ROA, FCF margin — how efficiently does the company make money? |
| Growth | 20 | Revenue growth, EPS growth — is the business expanding? |
| Financial Health | 20 | Debt/equity, current ratio, interest coverage — is the balance sheet solid? |
| Momentum | 20 | 52-week price performance, beta — how has the stock behaved recently? |
ETF / Fund categories
ETFs and funds are evaluated across four categories worth 25 points each:
| Category | Points | What it measures |
|---|---|---|
| Valuation | 25 | P/E ratio, P/B ratio — how is the fund priced vs its holdings? |
| Performance | 25 | 1-year and 3-year returns — historical track record |
| Risk | 25 | Beta, standard deviation — how volatile is the fund? |
| Cost | 25 | Expense ratio — how much does it cost to hold? |
Rating scale
Searching a ticker
Type any US stock or ETF ticker symbol into the search box and press Analyze. CerbyFi automatically detects whether it is a stock or an ETF — you do not need to choose.
- 1Type the ticker in the search box (e.g.
AAPL,NVDA,SPY,QQQ). - 2Press Analyze or hit Enter.
- 3Results appear on the right. Click Show metrics on any category to see the individual metric breakdown.
- 4Press + Watchlist to save the result for quick re-access later.
Watchlist
The watchlist appears in the left sidebar. It holds up to 10 items. Each card shows the ticker, asset type, score, and a color-coded bar. Click any card to re-run the analysis.
A free account is required to use the watchlist. Your watchlist is saved to the server and synced across all your devices — sign in on any browser and your watchlist will be there.
If you click + Watchlist while not signed in, the sign-in prompt will open automatically.
Creating an account
An account gives you a persistent watchlist and access to the portfolio feature.
- 1Click Register in the top-right corner.
- 2Enter your name, email address, and a password (at least 6 characters).
- 3Click Create account. You are logged in immediately.
To sign back in later, click Sign in and enter your email and password. You stay signed in for 30 days.
Portfolios
Portfolios let you group stocks and ETFs with a percentage allocation for each holding. CerbyFi calculates a weighted aggregate score across your entire portfolio — a single number that reflects how well the portfolio scores overall, weighted by how much of it each holding represents.
You must be signed in to use portfolios.
Creating a portfolio
- 1Sign in to your account.
- 2Click + New in the Portfolios section of the sidebar.
- 3Enter a name (e.g. "Tech watchlist", "Retirement", "Speculative").
- 4Your new portfolio appears in the sidebar. Click it to open the detail view.
Adding holdings
- 1Search for a stock or ETF using the main search box.
- 2Open the portfolio detail in the sidebar (click the portfolio name).
- 3Click + Add [TICKER] to this portfolio. The button appears automatically when you have a portfolio open and the analyzed ticker is not already in it.
- 4The holding is added with a suggested allocation. Edit allocations to adjust.
Editing allocations
Allocations represent what percentage of the portfolio each holding makes up. They must always add up to exactly 100%.
- 1Open a portfolio and click Edit allocations.
- 2Adjust the number inputs. A live total shows whether your allocations sum to 100%.
- 3When the total shows ✓, click Save.
Aggregate score formula
The portfolio aggregate score is the sum of each holding's score, weighted by its allocation percentage:
Aggregate Score = Σ ( allocationi / 100 ) × scorei
For example, if you hold two stocks — AAPL at 60% allocation with a score of 80, and TSLA at 40% allocation with a score of 50 — your aggregate score would be: (0.60 × 80) + (0.40 × 50) = 48 + 20 = 68.
Portfolio Optimizer — how it works
The optimizer answers one question: what allocation across your current holdings produces the highest possible aggregate score?
It does not suggest new stocks to add or remove. It works only with the holdings you already have and finds the best percentage split between them.
How to use it
- 1Open a portfolio that has at least 2 holdings with scores.
- 2Click the Optimize button.
- 3A panel appears showing your current aggregate score and the optimized score, plus the suggested allocation for each holding.
- 4Review the suggestions. If you are happy with them, click Apply Allocation to save.
- 5Click Optimize again to close the panel without applying.
The algorithm — plain English
The optimizer uses a greedy algorithm with two rules:
| Rule | Value | Why |
|---|---|---|
| Minimum per holding (floor) | 5% | Ensures every holding is represented — if you added it, it gets at least a small weight |
| Maximum per holding (cap) | 60% | Prevents extreme concentration in a single holding |
Here is what happens step by step:
- 1Give everyone the floor. Every holding starts at 5%. The remaining budget is 100% minus (5% × number of holdings). For example, with 4 holdings: 100% − 20% = 80% remaining.
- 2Rank by score. Holdings are sorted from highest score to lowest.
- 3Fill the best holding first. Give as much of the remaining budget as possible to the #1 ranked holding, up to the 60% cap. Since it already has 5% from the floor, it can receive up to 55% more (reaching 60% total).
- 4Move to the next holding. Give as much of whatever is left to the #2 ranked holding, again up to the 60% cap. Repeat until the budget runs out or all holdings have been given their cap.
Worked example
Suppose you have a 3-stock portfolio with these scores and current allocations:
| Stock | Score | Allocation | Contribution |
|---|---|---|---|
| AAPL | 80 | 20% | 16.0 |
| MSFT | 72 | 55% | 39.6 |
| TSLA | 38 | 25% | 9.5 |
| Total | 100% | 65.1 |
The optimizer applies its rules:
- 1Floor: each holding gets 5%. Remaining budget = 100% − 15% = 85%.
- 2Ranked order: AAPL (80) → MSFT (72) → TSLA (38).
- 3AAPL gets filled to the cap: already has 5%, gets 55% more → 60%. Remaining = 85% − 55% = 30%.
- 4MSFT gets filled to the cap: already has 5%, gets 30% more (cap is 55 headroom, but only 30 left) → 35%. Remaining = 0%.
- 5TSLA stays at floor: 5%.
| Stock | Score | Current | Optimized | Contribution |
|---|---|---|---|---|
| AAPL | 80 | 20% | 60% | 48.0 |
| MSFT | 72 | 55% | 35% | 25.2 |
| TSLA | 38 | 25% | 5% | 1.9 |
| Total | 65.1 | 75.1 ↑ |
The optimized allocation raises the aggregate score from 65.1 to 75.1 — a gain of 10 points — simply by shifting weight toward the highest-scoring holdings.
What the optimizer does NOT do
It is important to understand the limits of the optimizer:
- ✗It does not predict future performance. A high score today does not guarantee future returns.
- ✗It does not consider diversification, sector exposure, or correlation between holdings.
- ✗It does not account for your personal risk tolerance or investment horizon.
- ✗It does not suggest adding or removing holdings — only rebalancing what is already there.