How Your Portfolio Score Is Calculated in the Student Investor Challenge

Most participants in the Student Investor Challenge assume that whoever picks the best shares wins. That is partly true — but it misses the full picture. Your ranking in round one depends on a combined score drawn from two separate portfolios, a penalty rule for sitting on too much cash, and a starting-position adjustment for teams that register late. Once you understand each of these pieces, you can make decisions that genuinely improve your position — rather than hoping the market does the work for you. For the full rules, see the rules and portfolio guide.

What “portfolio value” actually means

Each team manages two virtual portfolios, and each begins at £100,000 in virtual cash. As the share prices in your portfolio move up or down each trading day, the total value of your portfolio changes with them.

Here is the key point: the score that matters for your ranking is percentage return, not raw pounds. If your portfolio is worth £108,400 at a given point in round one, your score is displayed as +8.4% — not as “£8,400 up.” This keeps the competition genuinely level. Two teams that started at the same time with the same £100,000 and the same shares will always have the same percentage return, regardless of any other factors. One team cannot gain an advantage simply by having a larger starting balance — everyone begins equal.

The two portfolios and the combined score

The Student Investor Challenge asks you to run two portfolios side by side: the Active and Strategic portfolios. They have different rules and reward different approaches.

Active Investor — your daily portfolio

The Active portfolio is designed for market engagement. You can trade as often as you like, reacting to news, results announcements, and market movements. It rewards participants who pay attention to what is happening in the market day by day. The Active portfolio generates its own percentage return, which feeds into your league position.

Strategic Investor — your long-term portfolio

The Strategic portfolio has a limited number of trades each month. It is designed to reward patience and considered decision-making rather than constant activity. Participants who select shares with a longer view — understanding the business, the sector, and the outlook — tend to do well here. Like the Active portfolio, the Strategic portfolio generates its own percentage return.

How the combined rank is formed

Your position in the main league table is based on both portfolios together. The top 250 teams from round one qualify for the semi-finals on their combined score. This has a direct practical implication: you cannot win on the Active portfolio alone while neglecting the Strategic one, and vice versa.

Consider two fictional teams:

• Team A puts all its energy into the Active portfolio and achieves a +14% return there. But they ignore their Strategic portfolio, which sits mostly in cash and earns +0.5%.
• Team B achieves +8% on Active and +11% on Strategic through careful, patient stock selection.

Team B will almost certainly rank higher on the combined score, even though Team A outperformed them on the Active side. Neglecting either portfolio is a real strategic risk.

The Windfall Tax — a hidden drag on your score

This is the rule that catches the most teams off guard. If you hold more than £15,000 in uninvested cash in either portfolio, a £1,000 deduction is applied every day until that cash balance falls below the threshold. This is the Windfall Tax, and it directly reduces your portfolio value — and therefore your percentage return.

Here is how quickly it adds up:

Idle cash held	Days elapsed	Total Windfall Tax	Portfolio value (from £100,000)
£30,000	10 days	£10,000	£90,000 (before market moves)
£30,000	20 days	£20,000	£80,000 (before market moves)
£30,000	30 days	£30,000	£70,000 (before market moves)

A team that leaves £30,000 idle for a month has already lost 30% of their starting balance to the Windfall Tax alone, before a single share has moved. Even a spectacular run in the shares they did buy would struggle to overcome that drag. The real-world lesson here mirrors what happens in professional fund management: cash sitting idle “costs” you the return you are not making. The practical tip is straightforward — keep uninvested cash below £15,000 in both portfolios from day one.

Index-linking — why joining late does not disqualify you

Teams that register and begin trading part-way through round one face an apparent problem: the market has already moved since the competition opened, so their starting position looks different from an early entrant’s.

The Challenge addresses this through FTSE 100 index-linking. When a team registers late, their opening balance is adjusted to reflect the FTSE 100 index movement from the start of round one to their registration date. If the FTSE rose 3% before your team signed up, your £100,000 starting balance is treated as though it also grew by 3% — so you are competing on a level footing from your actual start date.

This is not a disadvantage for early starters either. Each team’s percentage return is calculated from their own adjusted starting point. The adjustment simply ensures that late entrants are not penalised for the market’s movement during a period when they had not yet registered. Everyone competes from the same relative baseline.

Checking your live position

Your real-time ranking is visible on the portfolio league table. The table shows three separate positions for your team:

• Combined rank — your overall position based on both portfolios together. This is the one that determines semi-final qualification.
• Active Investor rank — where you stand on the Active portfolio alone.
• Strategic Investor rank — where you stand on the Strategic portfolio alone.

Reading the difference between these three numbers tells you something useful. If your combined rank is better (lower number) than your Active rank alone, your Strategic portfolio is pulling you up in the standings. If your combined rank is worse than your Active rank, your Strategic portfolio is dragging you down. That gap is the clearest signal of where to focus your attention. The table updates on live London market prices, so checking it regularly gives you a current picture of your position.

Five things that will move your rank this week

1. Deploy cash below the £15,000 threshold in both portfolios. This eliminates the Windfall Tax drag immediately. If you are currently above the threshold in either portfolio, this is the single highest-priority action.
2. Diversify across sectors. A portfolio concentrated in one or two sectors is exposed to sector-specific news. Spreading across different industries — technology, consumer goods, financials, healthcare, and so on — means that no single bad-news day can demolish your overall score.
3. Review your Strategic positions. The Strategic portfolio has limited monthly trades, so using them well matters. You do not need to trade frequently — even a once-a-month review to check that your positions still fit your original plan is enough. What you want to avoid is set-and-forget when a holding has clearly changed.
4. Follow results season. Company earnings announcements move share prices significantly on the day they are published. Understanding why shares move on earnings — and anticipating which of your holdings are due to report — is a practical edge in the Active portfolio.
5. Do not overtrade in Strategic. The Strategic portfolio has a limited trade allowance. Using trades reactively to cut a loss and chase something else rarely outperforms patience. Think of the Strategic portfolio as a long-term bet on businesses, not a tool for short-term price chasing.

Frequently asked questions

Does my rank reset at the semi-finals?

Round one and the semi-finals use entirely different scoring systems. The semi-final format switches from portfolio performance to market prediction — calling Friday closing prices — so your round-one percentage return does not carry over. It is a fresh competition with different mechanics. For detail on what the semi-finals involve, see our article on the four routes to the semi-finals.

Can one really bad trade destroy my overall ranking?

It depends on position size. A large concentrated position that falls sharply will hurt your percentage return significantly — this is why diversification matters. If you put 40% of a portfolio into a single share and it drops 25%, you have lost 10 percentage points off your score from that one trade alone. A bad trade in a small position, say 5% of the portfolio, has far more limited impact. Position sizing is one of the most underrated tools in the Challenge.

Is my portfolio visible to other teams?

No. Other teams can see your rank and your portfolio value on the league table, but not which shares you hold. Your individual positions remain private throughout round one. The leaderboard shows standings and values, not holdings.

What percentage return is competitive in round one?

There is no single target — it depends on how markets perform during the round. In a flat or falling market, even a small positive return can put you in the top 250. In a strongly rising market, you typically need to outperform the FTSE 100 to stay competitive. The live league table is the most reliable guide: look at where the top 250 cut-off sits right now and work backwards from there.