BIIB Stock Up 18% after 6-Day Win Streak
Biogen (BIIB) stock hit day 6 of a continuous streak of days with gains, with cumulative gains over this period amounting to a 18% return. The company has gained about $4.2 Bil in value over the last 6 days, with its current market capitalization at about $23 Bil. The stock remains 4.6% above its value at the end of 2024. This compares with year-to-date returns of 14.2% for the S&P 500.
BIIB provides therapies for neurological and neurodegenerative diseases, including treatments for multiple sclerosis, non-Hodgkin’s lymphoma, chronic lymphocytic leukemia, rheumatoid arthritis, and pemphigus vulgaris. After this rally, is BIIB still a buy – or is it time to lock in gains? Deep dive with Buy or Sell BIIB.
BIIB stock has jumped meaningfully recently and we currently find it fairly priced. This may feel like a caution, and there is significant risk in relying on a single stock. However, there is a huge value to a broader diversified approach we take with Trefis High Quality Portfolio. Trefis works with Empirical Asset Management – a Boston area wealth manager – whose asset allocation strategies yielded positive returns during the 2008-09 period when the S&P lost more than 40%. Empirical has incorporated the Trefis HQ Portfolio in this asset allocation framework to provide clients better returns with less risk versus the benchmark index; less of a roller-coaster ride, as evident in HQ Portfolio performance metrics.
Comparing BIIB Stock Returns With The S&P 500
The following table summarizes the return for BIIB stock vs. the S&P 500 index over different periods, including the current streak:
| Return Period | BIIB | S&P 500 |
|---|---|---|
| 1D | 3.0% | 0.0% |
| 6D (Current Streak) | 17.8% | 1.7% |
| 1M (21D) | 14.2% | 3.3% |
| 3M (63D) | 22.9% | 7.8% |
| YTD 2025 | 4.6% | 14.2% |
| 2024 | -40.9% | 23.3% |
| 2023 | -6.6% | 24.2% |
| 2022 | 15.4% | -19.4% |
What is the point? Momentum often precedes conviction. A multi-day win streak can signal growing investor confidence or spark follow-on buying. Tracking such trends can help you ride the strength, or prepare for a well-timed entry if momentum fades. However, big gains can follow sharp reversals – but how has BIIB behaved after prior drops? See BIIB Dip Buyer Analysis to learn more.
Gains and Losses Streaks: S&P 500 Constituents
There are currently 85 S&P constituents with 3 days or more of consecutive gains and 37 constituents with 3 days or more of consecutive losses.
| Consecutive Days | # of Gainers | # of Losers |
|---|---|---|
| 3D | 32 | 23 |
| 4D | 21 | 8 |
| 5D | 6 | 6 |
| 6D | 25 | 0 |
| 7D or more | 1 | 0 |
| Total >=3 D | 85 | 37 |
Key Financials for Biogen (BIIB)
Last 2 Fiscal Years:
| Metric | FY2023 | FY2024 |
|---|---|---|
| Revenues | $9.8 Bil | $9.7 Bil |
| Operating Income | $1.8 Bil | $2.2 Bil |
| Net Income | $1.2 Bil | $1.6 Bil |
Last 2 Fiscal Quarters:
| Metric | 2024 FQ4 | 2025 FQ1 |
|---|---|---|
| Revenues | $2.5 Bil | $2.4 Bil |
| Operating Income | $450.6 Mil | $625.2 Mil |
| Net Income | $266.7 Mil | $240.5 Mil |
While BIIB stock looks attractive given its winning streak, investing in a single stock without detailed, thorough analysis can be risky. The Trefis High Quality (HQ) Portfolio, with a collection of 30 stocks, has a track record of comfortably outperforming its benchmark that includes all 3 – the S&P 500, S&P mid-cap, and Russell 2000 indices. Why is that? As a group, HQ Portfolio stocks provided better returns with less risk versus the benchmark index; less of a roller-coaster ride, as evident in HQ Portfolio performance metrics.