No items tracked yet.
Add your first component or device to start tracking.
The LLM gathers published pricing — what distributors or retailers list right now. That's the purple column.
Your log is what you're actually paying. Quoted prices, PO prices, negotiated rates. That's the green column.
These two numbers are almost never the same. The gap between them tells you something important:
Your price is higher than published — You're overpaying. The market moved and your contract didn't. Time to requote.
Your price is lower than published — You have a good deal. Protect it. Don't renegotiate unless the market has dropped well below your rate.
Gap is growing — Something structural changed. Either the market is moving fast or your supplier is slow to adjust.
Gap is shrinking — Your pricing is converging with the market. Normal. No action unless it crosses over.
The derivatives work on both tracks. But the action you take depends on which track is moving and how they relate to each other.
Most people watch the number. The number is the least useful thing.
What matters is how the number is changing. And how that change is changing.
Current price and lead time (or availability). Observe. Establish your baseline. This is the number everyone watches. It's necessary but incomplete.
Price: What are we paying today? Lead time: How long until it arrives? For devices: is it in stock or backordered?
Price rising: Investigate. Test alternate suppliers or models. Learn which sources have buffer. Understand what's driving the movement before reacting.
Lead time growing: Supply is tightening. Parts that shipped in 4 weeks now take 6. For devices, "in stock" became "ships in 5 days." Start qualifying backup sources now. Don't wait for it to get worse.
Price falling: Monitor. Is this your item, the broader market, or one supplier running a promo? Diagnose before reacting. Don't mistake a blip for a trend.
Lead time shrinking: Supply is loosening. Pressure is easing. Good news — but don't renegotiate contracts yet. Confirm the trend holds for 2-3 weeks before using it as leverage.
Price accelerating up: Move from investigating to committing. Lock in contracts or place orders now. Build buffer stock if you can. The cost of waiting compounds every week.
Lead time accelerating out: The supply squeeze is intensifying. Went from 4 weeks to 6 last week, now 6 to 9 this week. Order immediately. Consider pre-buying. Notify your team or customers about potential delays before they become emergencies.
Price acceleration easing: Early warning. The price may still be rising, but the rise is losing steam. Defend your position. Watch for jerk confirmation.
Lead time acceleration easing: Lead times still growing, but the growth is slowing. The worst may be passing. Hold your current orders but don't panic-buy more. The supply chain is starting to recover — give it 2-3 weeks to confirm.
Price jerk positive: Act decisively. This is the window. Something fundamental is intensifying — a supply disruption, a new model launch, a tariff change. Make the reversible bets now.
Lead time jerk positive: Lead times are not just growing — they're growing faster every week. This signals a systemic disruption, not a blip. A factory shutdown, an allocation, a shipping crisis. Escalate internally. Secure any available stock today. Activate alternate suppliers you've already qualified.
Price jerk negative: Last best window. The current trend is about to shift. If you've been waiting for a better price, this may be the bottom. If you've been delaying a purchase, the window is closing.
Lead time jerk negative: Lead times are still long, but the growth is decelerating faster now. Recovery is forming. Don't cancel existing safety orders yet, but stop adding to them. Plan your return to normal ordering cadence over the next 3-4 weeks.
Price still rising but acceleration fading. Peak is near. Requote immediately. If you can hold off buying, better prices may be 2-4 weeks away.
Price still dropping but the decline is slowing. Bottom is forming. This is the buy window. Prepare purchase orders. Wait for velocity to flatten, then commit.
Stability period is ending. New movement is building but direction isn't clear yet. Secure flexible contracts now while suppliers are still relaxed.
Decline is accelerating further — but this jerk spike often signals the final push before reversal. Watch next 2 weeks for velocity sign change.
Your actual price (green column) is higher than the published price (purple column) AND the derivative pattern is shifting. You're overpaying in a changing market. Requote immediately. Use the published price as leverage.
Your actual price (green column) is lower than the published price (purple column) AND the market is shifting. You have a good deal. Don't renegotiate — you might lose your advantage. Lock in current terms and quantities if your contract allows it.
Lead times still long but the growth is slowing. The worst of the squeeze may be passing. Hold existing orders but stop panic-buying. Start planning your return to normal ordering in 3-4 weeks.
Lead times improving and the improvement itself is leveling off. Supply is normalizing. This is when to renegotiate contracts — suppliers have capacity again but haven't fully adjusted pricing. Your leverage window.
Lead times were steady, now something is stirring. Could be a factory issue, a logistics disruption, or sudden demand spike. Investigate immediately. If you can identify the cause, you're weeks ahead of competitors who only watch price.
Lead times were already growing and now they're growing faster. This is the escalation signal. Secure available stock immediately. Activate every alternate source. Alert your team and customers — this will affect delivery commitments.
When both price and lead time jerk change sign at the same time, something big is happening. A tariff announcement, a factory shutdown, an allocation event, a new product launch pulling supply. This is the strongest signal the framework produces. Treat it as urgent.
Price and lead time are telling different stories. Prices up but lead times down usually means supply is fine but demand is being manufactured (hype, speculation, or a competitor stockpiling). Don't overbuy. The price pressure may not last. Let lead time be your truth signal.
A derivative in calculus measures the instantaneous rate of change:
f′(x) = lim(Δt → 0) [ f(x+Δt) − f(x) ] / Δt
That limit requires continuous data. We have weekly observations. So we use the finite difference method — the standard approach for computing derivatives from discrete time-series data, used in physics, economics, signal processing, and engineering.
The Formulas:
Velocity = (this week − last week) ÷ time interval
Acceleration = (this week's velocity − last week's) ÷ time interval
Jerk = (this week's acceleration − last week's) ÷ time interval
With weekly data, the time interval is 1. The division doesn't change the number. But the formula is mathematically correct and works at any frequency.
Note: Financial derivatives (options, futures, swaps) are contracts. These are calculus derivatives — rates of change. Same word, different meaning.