Biotech Growth Trust PLC (BIOG) — Research Note

Executive summary

Biotech Growth Trust is a closed-end UK investment trust managed by OrbiMed that invests in global biotech equities, with a structural overweight to US small and mid-cap clinical-stage names (~80% US, ~16% China at 30 Sept 2025). After four poor years, the trust delivered a sharp +36.9% NAV per share total return in the six months to 30 September 2025, outperforming the NASDAQ Biotechnology Index (+10.6%) on the back of a small-cap biotech rally and M&A activity 2025-11 half-year. For valuation, the only sensible anchor is NAV — and the shares trade at a ~9.5% discount to NAV with an active buyback policy targeting a 6% discount.

Fair value estimate

Methodology: NAV-based. For a closed-end investment trust, fair value is the underlying NAV per share, adjusted for a sustainable trading discount given the trust's discount-control mechanism (buyback above 6% discount).

• NAV per share at 30 Sept 2025: 1,117.2p 2025-11 half-year
• NAV accretion from post-period buybacks (1.44m shares cancelled at ~9% discount): ~+0.7-1%, implying current NAV likely 1,150–1,250p (also factoring some sector movement)
• Sustainable trading discount: 5–8% (the Board defends 6% but the shares persistently overshoot in volatile periods)

Fair value range per share: 1,100p – 1,250p

• Implied market cap (using ~21.65m shares post-period buybacks): £238m – £271m
• Mid-point market cap: £254m
• Latest disclosed market cap: £248.9m
• Upside to mid-point: ~+2% (range −4% to +9%)

In other words: the shares are roughly at fair value. The principal driver of returns from here is the underlying biotech portfolio performance, not a re-rating of the discount.

Sector context

The classification (Financial Services / Financials) is correct in form — BIOG is a regulated investment trust — but it is effectively a sector-equity vehicle giving leveraged exposure to biotechnology. Quality/growth/leverage profile vs. typical financial-services peers: incomparable. Vs. its true peer set of biotech funds:

• Listed peers: International Biotechnology Trust (IBT), Polar Capital Global Healthcare (PCGH), RTW Biotech Opportunities (RTW), BB Biotech (BION, Swiss).
• BIOG is among the more aggressive on the small-cap/clinical-stage spectrum and runs higher discount volatility.

Investment thesis

1. NAV discount provides a margin of safety: Shares trade at ~9.5% discount with the Board actively buying back when discount exceeds 6%; 4.0m shares repurchased in H1 FY26 alone at an average 9.1% discount, accretive to NAV/share 2025-11 half-year. A continuation vote brought forward to 2028 also focuses the Board's mind on closing the discount.

2. OrbiMed has demonstrated stock-picking value in this cycle: H1 FY26 NAV return of +36.9% vs. benchmark +10.6%, driven by overweight small-cap positions in winners like Mineralys, Alnylam, Avidity and CG Oncology, and exposure to M&A targets (SpringWorks acquired by Merck KGaA; Avidity by Novartis post-period at a 46% premium) 2025-11 half-year. Management estimates >80% of NAV is in potential acquisition targets.

3. Sector valuations remain depressed vs. history: Median ratio of market cap to net cash for the biotech universe is below dot-com/GFC lows; ~10% of biotech still trades at negative enterprise value 2025-11 half-year. With Fed cutting and political overhangs (drug pricing, tariffs, RFK Jr.) dissipating, this is plausibly an early-cycle recovery rather than a fully-played one.

Key risks

1. High volatility / drawdown risk: NAV fell from 1,446p (Mar 2021) to 815.9p (Mar 2025) — a 44% drawdown — before recovering 2025-11 half-year, 2021-11 half-year. The portfolio's small-cap, binary-clinical-event nature means turnover is very high and single positions can swing 80%+ on data.

2. China and geopolitical exposure: 15.7% of portfolio in Chinese biotech; PD-1/VEGF deals, tariffs, FTC/HHS uncertainty all risk factors 2025-11 half-year. Prior China write-downs (StemiRNA 74% mark-down in FY24, New Horizon Health to nil) demonstrate the risk in unquoted China names.

3. Continuation risk and size shrinkage: AGM 2025 continuation vote secured only 77% support; a dissenting institutional shareholder remains active. Board has brought forward the next continuation vote to 2028 (from 2030). Buybacks have shrunk NAV from £601m (Sept 2021) to £258m (Sept 2025) — a structurally challenged shareholder register could force wind-up at NAV minus realisation costs 2025-11 half-year, 2025-07 AGM result.

Operating leverage

There is no operating leverage in this entity. As a closed-end fund, costs are management fees (OrbiMed portfolio management fee + AIFM fee ≈ 1.3% ongoing charges on NAV), broadly proportional to assets. A 20% NAV beat does not flow into "earnings" — there is no earnings line in the operating sense. There is a performance fee but it requires recovering prior underperformance before crystallising (none currently accrued) and is capped/staggered 2025-11 half-year. Gearing of 9.3% adds market exposure but is not the kind of operating leverage this investor seeks. This driver scores very low for the user's strategy.

Value-trap signals

• Persistent discount widening to NAV during the multi-year drawdown (5–10% range, occasionally wider).
• Shrinking AUM through buybacks — fee scale is eroding.
• Continuation-vote dissent at 23% suggests a non-trivial part of the register would prefer realisation.
• NAV per share has not recovered to 2021 highs (1,117p vs. 1,446p+ in 2021), so absolute returns over five years are negative despite the recent rally.

These are not "fraud" signals but they are structural overhangs.

Earnings vs. expectations

Not directly applicable to a closed-end fund. The relevant track record is NAV vs. benchmark:

• FY24 H1 (Sept 2023): NAV −4.1% vs. benchmark −3.0% → miss.
• FY25 H1 (Sept 2024): NAV +2.7% vs. benchmark +1.4% → beat.
• FY26 H1 (Sept 2025): NAV +36.9% vs. benchmark +10.6% → strong beat.

Pattern: a multi-year period of underperformance has given way to two consecutive halves of outperformance. The small-cap-heavy strategy is highly cyclical — beats and misses come in long swings, not quarter by quarter 2024-11 half-year, 2025-11 half-year.

Conviction

Conviction: 4 (high). For an investment trust, NAV is a transparent, audited, daily-published number; methodology is unambiguous. Anchors: (i) NAV is reported and Level-1 marked for >98% of investments; (ii) the discount is bounded by an active buyback policy and a 2028 continuation vote; (iii) market cap and NAV are within ~5% of each other already, so the fair-value call is not heroic. Caveats: (i) underlying NAV is highly volatile so the point estimate moves daily; (ii) ~0.4% of NAV is Level-3 unquoted with significant uncertainty.

Overall assessment vs. investor profile

This is a biotech equity fund, not an AI-receiver. The user wants companies that capture value as AI scales — picks-and-shovels, vertical SaaS, AI-pharma platforms with their own data, etc. BIOG's underlying holdings are mostly clinical-stage drug developers; some have AI-discovery angles (e.g. prior crossover into QuantumPharm/XtalPi was AI-driven) but this is not the fund's strategic emphasis 2024-11 half-year. There is zero operating leverage at the trust level. The valuation is reasonable (small discount to NAV) but does not provide the asymmetric upside the user is looking for. This stock is outside the strategy for the user's portfolio.