BIOGEN IDEC INC

BIOGEN IDEC INC insiders are currently net buyers of BIIB stock, showing bullish sentiment over the past 90 days. Executives have purchased $183.0M while selling $70.1M, resulting in a positive net flow of $112.9M. This buying activity represents 72% of total transaction volume.

BIOGEN IDEC INC has 46 active insiders who have filed SEC Form 4 transactions in the past 90 days. Alexander J. Denner (Executive) leads with 22 transactions totaling $177.1M. George A. Scangos (Executive) follows with 38 transactions worth $19.6M. Open-market purchases require insiders to invest their own capital, demonstrating genuine conviction.

The Insider Alignment Score measures the ratio of buying to selling activity on a 0-100 scale. BIOGEN IDEC INC's current score of 72/100 indicates bullish insider sentiment. Scores above 60 suggest insiders are accumulating shares faster than selling, reflecting $183.0M in purchases versus $70.1M in sales.

The most recent insider transaction occurred on Feb 2, 2026, when Singhal Priya (Head of Development) disposed of 748 shares at $179.30 per share for $134.1K. This appears to be a discretionary trade.

Based on SEC Form 4 filings from the past 90 days, BIIB insider trading sentiment is currently bullish with an Alignment Score of 72/100. The net insider flow of $112.9M reflects accumulation, with 72% of volume being purchases.

SEC Form 4 is the primary disclosure mechanism for insider trading at publicly traded companies like BIOGEN IDEC INC. Corporate insiders must file within two business days of any transaction, making it one of the most timely sources of executive sentiment. At BIIB, we track all Form 4 filings—currently showing 1000 transactions from 46 insiders over 90 days.

A 10b5-1 plan allows BIOGEN IDEC INC executives to pre-schedule stock sales when they don't possess material non-public information. At BIIB, approximately 20% of recent transactions are 10b5-1 trades. The remaining 80% are discretionary trades, which may carry more informational value.

You can monitor BIOGEN IDEC INC (BIIB) insider trading activity on this page, which updates within hours of new SEC Form 4 filings. We track all 46 active insiders and provide real-time transaction feeds, the Alignment Score, 10b5-1 vs. discretionary breakdowns, and direct links to SEC EDGAR filings.

Our Alignment Score measures the ratio of insider buying to selling on a scale of 0-100. A score above 70 indicates strong bullish sentiment, while below 30 suggests bearish activity. BIOGEN IDEC INC's current score of 72/100 indicates strong bullish sentiment with executives accumulating shares. This is calculated from $183.0M in purchases versus $70.1M in sales over 90 days, resulting in a net flow of $112.9M.

SEC Form 4 filings are mandatory reports that BIOGEN IDEC INC insiders must submit within 2 business days. Each filing includes the insider's name, relationship, transaction type, shares, and price. Transaction codes: P (purchase), S (sale), A (award), M (option exercise), G (gift). At BIIB, the most common type is "M" with 23 occurrences. The most recent Form 4 was filed on Feb 2, 2026 by Singhal Priya.

Rule 10b5-1 allows corporate insiders to establish pre-scheduled trading plans when they don't possess material non-public information. At BIOGEN IDEC INC, approximately 20% of recent transactions are executed under 10b5-1 plans, while 80% appear to be discretionary trades. The low percentage means most insider activity at BIIB represents discretionary decisions with more informational value.