Upstream Bio, Inc.

Upstream Bio, Inc. insiders are currently net sellers of UPB stock, showing bearish sentiment over the past 90 days. Total sales of $6.5K outpace purchases of $0, creating a net outflow of $6.5K.

Upstream Bio, Inc. has 11 active insiders who have filed SEC Form 4 transactions in the past 90 days. Adam Houghton (Chief Business Officer) leads with 1 transactions totaling $6.5K. Allison Ambrose (Executive) follows with 1 transactions worth $0. 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. Upstream Bio, Inc.'s current score of 0/100 indicates bearish insider sentiment. Scores below 40 indicate selling pressure exceeds buying. Insider selling often reflects diversification needs, tax optimization, or estate planning.

The most recent insider transaction occurred on Mar 16, 2026, when Houghton Adam (Chief Business Officer) disposed of 699 shares at $9.29 per share for $6.5K. This appears to be a discretionary trade.

Based on SEC Form 4 filings from the past 90 days, UPB insider trading sentiment is currently bearish with an Alignment Score of 0/100. The negative net flow of $6.5K shows more selling than buying. However, 11% of recent transactions are 10b5-1 scheduled trades.

SEC Form 4 is the primary disclosure mechanism for insider trading at publicly traded companies like Upstream Bio, Inc.. Corporate insiders must file within two business days of any transaction, making it one of the most timely sources of executive sentiment. At UPB, we track all Form 4 filings—currently showing 19 transactions from 11 insiders over 90 days.

A 10b5-1 plan allows Upstream Bio, Inc. executives to pre-schedule stock sales when they don't possess material non-public information. At UPB, approximately 11% of recent transactions are 10b5-1 trades. The remaining 89% are discretionary trades, which may carry more informational value.

You can monitor Upstream Bio, Inc. (UPB) insider trading activity on this page, which updates within hours of new SEC Form 4 filings. We track all 11 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. Upstream Bio, Inc.'s current score of 0/100 indicates bearish sentiment with significant insider selling pressure. This is calculated from $0 in purchases versus $6.5K in sales over 90 days, resulting in a net flow of -$6.5K.

SEC Form 4 filings are mandatory reports that Upstream Bio, 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 UPB, the most common type is "C" with 11 occurrences. The most recent Form 4 was filed on Mar 16, 2026 by Houghton Adam.

Rule 10b5-1 allows corporate insiders to establish pre-scheduled trading plans when they don't possess material non-public information. At Upstream Bio, Inc., approximately 11% of recent transactions are executed under 10b5-1 plans, while 89% appear to be discretionary trades. The low percentage means most insider activity at UPB represents discretionary decisions with more informational value.