Alex Rivera
Breaking News Editor
Breaking News Editor at 13F Insight. First to report on major SEC filings, institutional moves, and regulatory developments.
A note from Alex
Hey, I'm Alex. I spent three and a half years at Bloomberg writing breaking-news pieces about the kind of trades that move tickers in after-hours, and what I learned is that the news cycle moves a lot faster than the explanations do.
That's the gap I'm here to close. When a major insider files a Form 4 at 4:31pm, you should know about it by 5:00 — not in tomorrow's morning newsletter. And you should know what's actually new about it, not just that it happened.
I'll keep my pieces short, my numbers exact, and my opinions out of the lede. If something I wrote ages badly, I'll say so on the record.
Articles by Alex Rivera (827)
- News
Garrett Motion Executive Sells $13.5M in GTX Stock Across Two Weeks — More Than the Award He Just Received
Garrett Motion executive Olivier Rabiller received a 456,461-share award on Feb 11 and then sold 662,963 shares ($13.5M) over two weeks — offloading far more than he was granted.
- News
Bloom Energy Officer Cashes Out $8.1M in BE Stock via Exercise-and-Sell at 475% Gain
Bloom Energy officer Shawn Soderberg exercised options at $31 and immediately sold at $178-180, netting $8.1M in a single day — her third major sell-off in four months.
- News
Arcellx CEO Rami Elghandour Sells $10.2M in ACLX Stock After Option Exercises and Share Gifts
Arcellx CEO and founder Rami Elghandour sold nearly 90,000 ACLX shares worth $10.2M on Feb 27 — part of a structured liquidity sequence that included option exercises and share gifts earlier in the month.
- News
Axsome Therapeutics COO Exits Entirely as He and Director Sell $9.8M in AXSM Stock
Axsome Therapeutics COO Mark Jacobson sold his entire remaining position worth $5.7M while Director Mark Coleman sold $4M on the same day — a coordinated $9.8M insider exit.
- Research
Insider Selling and 10b5-1 Plans: Identifying Real Red Flags
A practical 10b5-1 filter that helps investors distinguish routine insider selling from meaningful risk signals.
- News
Salesforce's Top Two Insiders Sold $35M in CRM Stock Last Quarter — Here's the Breakdown
CEO Marc Benioff and CTO Parker Harris combined for over $35 million in Salesforce stock sales during Q4 2025, with Harris executing a single-day $31.6M exercise-and-sell on December 2.
- News
Atlassian Co-Founders Sell $4M in TEAM Stock in Coordinated Week-Long Dump
Both Scott Farquhar and Mike Cannon-Brookes sold thousands of Atlassian shares across Jan 23-28 in near-identical transaction patterns, totaling approximately $4M in combined dispositions.
- Research
Mubadala's $17.5B Q4 Filing: 90% GlobalFoundries, Quantum Computing Bets, and a $631M Bitcoin Play
Abu Dhabi's Mubadala sovereign wealth fund holds 90% of its $17.5B portfolio in GlobalFoundries, added $631M in Bitcoin via IBIT, and opened positions in 4 quantum computing stocks in Q4 2025.
- Research
Windacre Doubled Its Portfolio to $9.3B in One Quarter and Made Roper Technologies Its Biggest Bet Ever
Snehal Amin's Windacre Partnership surged from $4.4B to $9.3B in a single quarter, deploying $4.9B across 7 new positions headlined by a brand-new $1.38B bet on Roper Technologies that the fund had never previously held.
- Research
Soros Pivots to Energy and AI Infrastructure - Q4 2025 Portfolio Surges 23%
Soros Fund Management's Q4 2025 13F reveals a bold pivot to energy options (XOP, XLE) and AI infrastructure (CoreWeave, Kodiak AI), with the portfolio surging 23% to $8.6B across 244 assets.
- Research
Soros Pivots to Energy & AI Infrastructure — Q4 2025 Portfolio Surges 23% to $8.6 Billion
Soros Fund Management's Q4 2025 13F reveals a bold pivot to energy ETFs (XOP, XLE puts) and AI infrastructure (CoreWeave, Kodiak AI), with AUM surging 23% to $8.6 billion. 115 new positions opened, heavy convertible bond exposure, and a massive energy hedge signal Soros's signature asymmetric macro strategy.
- Research
Farallon Slashed $2.5B in Credit Hedges and Built a $6.8B Biotech Empire While Dumping Bitcoin: Inside the Q4 2025 Pivot
Tom Steyer’s Farallon Capital cut its HYG put position by 80% — from $3.17B to $645M — while deploying billions into Revolution Medicines, Natera, and BridgeBio. The $42B fund also dumped 77% of its Bitcoin ETF.
- Research
State Street Q4 2025: Low Turnover, Higher AUM, and a Core Beta Rebuild
STATE STREET CORP reported $2980.91B in Q4 2025 13F assets with top-10 concentration at 31.36%. We break down what changed and what retail investors can act on.
- Research
Pershing Square's Q4 2025 Pivot: $2.22B in Amazon, $1.76B in Meta, and a 25.2% Portfolio Expansion
Pershing Square expanded its 13F portfolio by 25.2% quarter-over-quarter in Q4 2025, adding Amazon and Meta as major new positions while Brookfield became the top holding.
- Research
Pzena Hits $33.4B Record AUM With Auto Parts at #1 and 13.8% of Baxter — Inside the Deep Value Machine's Q4 2025 Filing
Pzena Investment Management hit an all-time high $33.4B AUM in Q4 2025 with Magna International as its #1 holding. The deep value firm owns 13.8% of Baxter International, 11.7% of Skyworks, and 11.3% of Amdocs — with zero FAANG stocks in its top 25.
- Research
Capital One at 9.4% and Five Other Banks: Inside Chris Davis's $22B Financials-First Q4 2025 Portfolio
Chris Davis allocates 32%+ to financial stocks—led by a monster 9.4% Capital One position—while trimming Big Tech. A deep dive into the third-generation value investor's Q4 2025 playbook.
- Research
Harnisch Put 91% of Peconic’s $4.2B Into Three Infrastructure Stocks After Returning 79% in 2025: The Power Grid Play That Crushed the S&P 500
Bill Harnisch’s Peconic Partners exploded from $140M to $4.2B in Q4 2025 by going all-in on Quanta Services, Dycom, and MasTec — the companies building the power lines and fiber networks behind AI, broadband, and clean energy.
- Research
Abrams Capital Put 38% of a $5.7B Portfolio Into One Aerospace Stock While Building a $1.3B Auto Dealership Empire: Inside the Klarman Protégé's Q4 2025 Conviction Bet
David Abrams — Seth Klarman's former protégé — held 32 million LOAR shares worth $2.2B at 38.4% of portfolio in Q4 2025 while deploying $1.33B into Lithia Motors and Asbury Automotive, the two largest US auto dealership chains. 12 holdings, 3 stocks = 62% of the portfolio.
- Research
Akre Deployed $2.65B Into 8 New Positions After Pruning to Just 11 Holdings: Inside the Compounding Machine Reload of Q4 2025
Akre Capital rebuilt its portfolio from 11 to 18 holdings in Q4 2025, deploying $2.65B into Moody’s, Airbnb, FICO, and Roper Technologies while increasing Brookfield by 40% — the most aggressive single-quarter expansion in the fund’s recent history.
- Research
Gates Sold $1.9B of Berkshire and Microsoft in Q4 as the Foundation's 20-Year Self-Destruct Accelerates: Inside the $35.4B Blue-Chip Portfolio
The Gates Foundation Trust sold 2.36M Berkshire and 1.5M Microsoft shares in Q4 2025 — its only two trades — as Bill Gates's 20-year sunsetting plan systematically unwinds a $35.4B blue-chip portfolio.