On April 24, 2026 (Eastern Time), the quantum security startup Project Eleven presented a "Q-Day" medal along with 1 bitcoin to independent researcher Giancarlo Lelli. Lelli had just launched a significant quantum attack based on a variant of Shor's algorithm on elliptical curve encryption using publicly available quantum hardware: he successfully recovered a 15-digit ECC private key from a search space consisting of approximately 32,767 candidate keys. Just 19 months prior, the largest public demonstration available in the industry was still a 6-digit key experiment from September 2025, but now the scale of the attack has been magnified by about 512 times.

While mainstream technical opinions emphasize that Bitcoin currently relies on a 256-bit elliptical curve public key system, and the security redundancy between the 15-digit and the 256-bit keys spans multiple orders of magnitude, it is still too early to discuss “direct threats” in the short term; on the other hand, it is impossible to deny that the timeline from 6 digits to 15 digits has formed a clear rising curve — this resembles the sound of a “gunshot” signaling a push for quantum-resistant migration, and the term Q-Day, which once carried a hint of sci-fi, has finally been placed on the real-time schedule.

On the same day, another narrative in Bitcoin saw funding quietly rise. On April 24, Bitcoin spot ETFs recorded a net inflow of approximately $14.4489 million in a single day, marking the ninth consecutive trading day of net inflows. As the primary channel through which institutions and compliant funds allocate Bitcoin exposure, such continuous accumulation is often interpreted as a signal of bullish long-term views on price and asset status — according to data from a single source, BlackRock's IBIT saw a net inflow of approximately $22.8790 million on that day, with a historical cumulative net inflow of around $190 million, adding a more tangible number to this “buying” sentiment.

The narrative around pricing models further reinforced the imagined bottom. Quantitative trader Killa (@KillaXBT), based on "decreasing cycles" and "pattern recognition," constructed a cyclical model that predicted a top of $121,362 during the last bull market, while the actual top was around $126,100, with an error of about 3.9%. This past achievement makes his new conclusion in the current cycle particularly striking: the "fundamental bottom" of the current bear market is near $38,800, with an expected bottom range lying between $40,740 and $42,680 — of course, this remains a personal judgment based on historical data and models, and carries significant uncertainty.

Thus, the picture becomes nuanced: on one side is the quantum attack leaping from 6 digits to 15 digits, marked as a technical milestone of “Q-Day countdown”; on the other side lies the continuous net inflow of ETFs for 9 days, alongside traders delineating a “buying window” through specific price ranges. The shadow of the quantum countdown and the sparks of funding accumulation begin to collide on the same timeline, as Bitcoin's next fate is being repriced between these two forces.

Quantum Breakthrough of 15-Digit Key

Project Eleven presented this year's "Q-Day" award, along with the 1 bitcoin prize, to Giancarlo Lelli, not because he authored an outstanding paper, but because he pushed an attack previously limited to "toy-level" to a whole new scale on a true quantum machine — the largest publicly recorded ECC quantum attack to date.

What Lelli accomplished can be summarized in one sentence: he executed a modified Shor's algorithm on publicly accessible quantum hardware to launch a real quantum attack on elliptical curve encryption, and then successfully "lifted" a 15-digit ECC private key from noise within a search space of approximately 32,767 candidate keys. The magnitude of the key space has risen from a few thousand to nearly thirty thousand; this is no longer a theoretical exercise on a whiteboard, but has moved theoretical constructs to real callable devices.

The term "leap" really shines in comparison: in September 2025, the largest public-scale ECC quantum demonstration was only a 6-digit key, and back then, the attack felt more like a proof of concept; more than a year later, Lelli raised this number to 15 digits. While it might seem that the increment is simply an additional 9 digits, in terms of key space, this represents an increase of about 512 times — each step forward means a synchronously raised capacity of quantum bits, error correction, noise control, and an entire array of engineering abilities.

It is this leap of 512 times that causes this 15-digit attack to be interpreted as a signal light: the real threat of quantum computing to cryptography is rapidly approaching from the "theoretical endpoint" to "engineering midway." Lelli's experiment itself is still far from shaking the security boundaries of the 256-bit elliptical curve but is enough to announce a more unsettled fact — the time interval from 6 digits to 15 digits may become a reference for the future iteration speed of quantum attacks, rather than an upper limit.

256-Bit Bitcoin Still Temporarily Safe

Bringing the focus back from the quantum laboratory to Bitcoin itself, what it truly relies on today is still the set of 256-bit public and private key systems based on elliptical curves. What Lelli demonstrated was recovering a 15-digit ECC private key within about 32,767 candidate keys — a striking technical demonstration, but compared to the reality of the 256-bit key, there exists a chasm of multiple orders of magnitude in security redundancy.

From 6 digits to 15 digits, the “searchlight” of quantum attacks has certainly brightened significantly, and the scale of attacks has increased by about 512 times; yet, it still revolves in the toy world of tens of thousands. What genuinely protects the Bitcoin network is a key space that far exceeds the limits of human intuition. Even with the support of quantum algorithms, climbing from 15 digits to 256 digits cannot be a gap that can be bridged by “doing a few more experiments,” but a long journey spanning engineering, hardware, and physical limits.

This is also why the mainstream judgment formed in the crypto industry after April 24, 2026, is quite consistent: the 15-digit ECC quantum breakthrough is an important milestone, but in the foreseeable short term, it does “not constitute a direct security threat” to the 256-bit elliptical curve keys used by Bitcoin. In other words, the 256-bit key you hold today will not be immediately exposed to quantum scrutiny just because Lelli pressed the run button a few times in the lab.

However, “temporarily safe” does not mean “can be ignored.” The same group of security researchers, when providing risk assessments, almost all added another footnote: this event feels more like a countdown signal for "accelerating quantum migration." What is truly unsettling is not the 15 digits themselves, but the underlying iterative speed implied by the timeline from 6 digits in September 2025 to 15 digits in April 2026 — if this curve continues to rise, the window available for Bitcoin and the entire crypto industry to respond may be shorter than imagined.

Thus, the question transitions from “Is it dangerous today?” to “How to achieve an orderly migration before actual danger approaches?” For the Bitcoin community, this means several topics that will inevitably be put on the table: when and how to introduce anti-quantum measures at the protocol layer; how to design new address and signature formats that allow ordinary users to conduct large-scale key rotation without being swept up in panic; and how to find a feasible compromise between protecting the security of existing assets, controlling on-chain migration costs, and avoiding consensus fragmentation.

Lelli’s 15-digit private key crack may not shake the security boundary of the 256-bit Bitcoin, but it has pulled these issues, originally pushed into the future, back into the present. For those still holding 256-bit keys, today remains on the safe side; but for those responsible for maintaining this system, the countdown has begun, and whether they can lead Bitcoin towards a quantum-resistant new stack before quantum attacks truly escalate to higher digit orders is the real difficulty curve of this story.

ETF Nine Days of Fund Inflow by Institutions

As the countdown on the technical front has just been sounded, the funding side is expressing its stance in another way.

On April 24, 2026, Bitcoin spot ETFs recorded a net inflow of approximately $14.4489 million on that day, maintaining a net inflow for the ninth consecutive trading day. Nine “positive inflow” daily lines lined up in a row, and compared to the panic and debate on the emotional layer, the funds provide a cold and hard-to-refute answer: from the perspective of compliant funds, Bitcoin still warrants continued accumulation.

If we consider these nine days as a record of voting on the funding side, BlackRock's IBIT stands at the most prominent position. According to data from a single source, on April 24, IBIT saw a net inflow of about $22.8790 million in a single day, even surpassing the total net inflow of all spot ETFs on that day, indicating that some funds not only did not reduce their holdings due to the news of quantum attacks but chose to increase their Bitcoin exposure on the same day.

Looking further back, the historical cumulative net inflow of IBIT since its launch has reached about $190 million (based on a single-source report). This is not a one-time violent purchase of betting, but rather a result of continuous inflows over multiple days and transactions within a regulatory framework — a typical institutional funding rhythm. For these institutions, spot ETFs are the primary compliant channel for entering Bitcoin, and continuous net inflows usually indicate that they view this asset's price and status with a mid to long-term perspective, rather than being swayed by short-term technical news.

On one side is the quantum breakthrough curve moving from 6 digits to 15 digits, interpreted as the countdown prior to “Q-Day”; on the other side is the continuous net inflow curve of the ETF for 9 days, especially with IBIT's inflow of tens of millions in dollars per day and hundreds of millions in cumulative inflow, continuously elevating the benchmark for institutional holdings. The technical side warns that the system must prepare for contingencies, while the funding side uses real money to answer another question: in the foreseeable mid to long term, they still wish to regard Bitcoin as a worthwhile bet.

Fear and greed thus manifest as two lines: one is the progress bar of quantum computing capability moving from 6 digits to 15 digits, and the other is the funding curve of ETF net inflows increasing from 1 day to 9 days, from millions to hundreds of millions of dollars. What truly determines the direction of the narrative is not which line is more frightening, but which line moves faster on the timeline.

Quantitative Veteran Draws the Bear Market Bottom Line

As the “quantum progress bar” and the “ETF funding curve” intersect on the screen, a third line is quietly added — this is the price cycle line drawn by quantitative trader Killa (@KillaXBT).

Killa's way of viewing the market, rather than saying it is “faith,” it is more about “statistical preference.” Based on "decreasing cycles" and "pattern recognition," he built a Bitcoin cycle model: each round of the market has been decreasing in its length of time and range of increase and decrease, with repeating rhythms and shapes surfacing in the price curve, which he considers quantifiable "patterns," repeatedly fed into the model for fitting. He never discloses concrete parameters, only leaving behind conclusive price ranges for the market to verify.

The last bull market was when this model was first widely remembered. At that time, he predicted a bull market top of $121,362, while the eventual actual top was around $126,100, with a deviation of about 3.9%. For some followers, this 3.9% is enough to be packaged as “almost hitting the ceiling”; for those who have really built the model, it is also a reminder — the model happened to be accommodated by the market during that round, but any approach to the top is laden with numerous uncontrollable random factors, and it does not guarantee that the next round will cooperate in the same way.

Now, in this cycle where quantum security is stepped up and institutions continue to net buy through spot ETFs, Killa, using the same “decreasing cycles + pattern recognition” framework, has provided a more alarming answer: he believes the "fundamental bottom" of this Bitcoin bear market lies around $38,800. This level, in his narrative, feels more like a theoretical "floor line" — a core coordinate compressed from all historical cycles.

But merely providing one line is insufficient to soothe market sentiment. Thus, he further delineated a broader buffer zone outside of this floor line: between $40,740 and $42,680 — this is his expected bear market bottom range. For many traders, these numbers quickly become new psychological anchors: dropping to above $42,000 is interpreted as a “normal correction”; touching slightly above $40,000 is viewed as “left-side positioning”; and if someone marks $38,800 on the chart, that line resembles the red line at the bottom of the screen — dropping below it means the narrative must be rewritten.

The issue is, even if the 3.9% error from the last round gave him a certain reputation for “accuracy,” Killa himself does not deny that these numbers remain personal predictions based on historical data and model deduction: whether the foundational bottom at $38,800 or the range of $40,740–$42,680, they lack any guarantee of occurrence, filled with subjectivity and uncertainty. In other words, they serve more as the urgent “story coordinates” that the market desperately needs between quantum anxiety and funding greed — giving each candlestick a relatable narrative.

Within this coordinate system, the progress bar of quantum breaks is responsible for generating fear of "will the future break," while the curve of ETF net inflows serves to prove “some still dare to buy now," and the levels of $38,800 and the range of $40,740–$42,680 drawn by Killa respond to another more straightforward question: if a drop does occur, where does it count as "just right enough"?

Quantum Countdown and the Funding Dispute

When spreading out the timeline, the scene appears bizarre: on one side is the leap from the 6-digit ECC demonstration in September 2025 to Lelli's extraction of the 15-digit ECC private key from approximately 32,767 candidates in April 2026 — an attack scale leap of 512 times; on the other side, the same day saw Bitcoin spot ETFs recording about $14.4489 million in net inflows, continuing the ninth consecutive trading day of adding positions, with BlackRock's IBIT pulling in about $22.8790 million in a single day, and historical cumulative net inflows reaching approximately $190 million according to a single source. The technical curve warns of a “future potential breakdown,” while the funding curve proves “people are still buying now.”

The mainstream industry judgment is, on one hand, quite calm: the 15-digit ECC cracks are distant from the 256-bit elliptical curve keys used by Bitcoin, interspersed with multiple orders of security redundancy, making it pitch impossible to discuss direct threats in the foreseeable short term; on the other hand, it clearly sees this as a “countdown signal” — not as an immediate problem but as an indication that we should start planning for the post-quantum security migration route starting today. It is within this context that “Q-Day” transforms from a distant sci-fi term into a box that needs to be filled in on risk control forms.

Market participants' strategic choices are thus torn between this technical countdown and the net inflow of funds, leading to three typical paths.

● Some institutions will treat the current stage as a window for “early positioning”: while mainstream views still agree on the short-term security of 256-bit keys, and continuous net inflows from ETFs provide a bullish signal from a mid to long-term perspective, they will use funds to bet on Killa’s model near the $38,800 “fundamental bottom” and the $40,740–$42,680 range. Their premise is that the real quantum threat will likely arrive later than the end of this price cycle.

● Others will choose to watch and manage positions rather than make directional bets until the narrative around Q-Day becomes clearer and prices fall into a range they are willing to acknowledge. For these individuals, Killa’s range is not a buying signal but rather a reference coordinate for “whether it's time yet”; the 9 consecutive net inflows of ETFs may not necessarily be seen as a reason to follow but may be understood as noise indicating “others are already dancing on stage.”

● The third group will simply shift focus from trading to technology: rather than hastily signaling buy or sell, they will invest resources into researching and proving quantum-resistant solutions — whether supporting post-quantum cryptography research teams or pushing the community to discuss migration paths at the governance level early on. For them, true alpha lies not in the thousands or tens of thousands of dollars’ fluctuations but in whether a future protocol upgrade can be completed smoothly and reliably.

This differentiation also makes the upcoming observatory points extremely crucial. First, will the scale of quantum attacks continue to stair-step upward from “6 digits → 15 digits”? — even if Bitcoin's 256-bit keys remain secure, the steepness of the attack curve will directly alter market perceptions of the Q-Day timetable. Second, when will the Bitcoin community transition from “we should start thinking about this” to “substantive discussions on promoting quantum resistance routes”? — when migration schemes and timelines are first written into BIPs and extensively debated, that will be a turning point significant enough to alter the narrative. Third, whether there will be a turning point in ETF funding flows — if the rhythm of continuous net inflows is interrupted or even turns into sustained net outflows amid the rising news of quantum progress and discussions on quantum resistance, it will indicate a reassessment by the funds that were previously bullish mid to long-term on the underlying technology risk.

Until then, the market can only oscillate back and forth between these two leads: one being the evolution of quantum attacks from 6 digits to 15 digits pressuring a “migration countdown” for all systems built on the elliptical curve; the other being the continuous accumulation of ETFs and the psychological bottom drawn by Killa, providing a price anchor for the current cycle. The former represents a long-term risk that will inevitably need to be realized, while the latter represents an ongoing short to mid-term opportunity. The true game is not “believing or not believing in quantum,” but rather which side of this timeline you stand on, and how much you are willing to pay for uncertainty in either segment.

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