Bitcoin (BTC) fell nearly 3% on Thursday after attempt to break above the $85,000 level was rejected, with the price returning to the $81,500 area in the wake of Tesla's third-quarter earnings report.

Key points:

• Bitcoin retreated toward $81,500 after Tesla reported a lower-than-expected Q3 capital expenditure (capex) of $4.73 billion.
• South Korea's KOSPI Composite Index saw fresh weakness, closing down 3.52% on Thursday.
• BTC price action was rejected from a resistance trend line at $84,840, preserving the pattern of lower highs.

Tesla capex underspend raises questions

Data from TradingView showed BTC/USD retracing around Wednesday's daily close before slipping back below $82,000. The pair gave back the entirety of the gains made during that session, when price peaked at around $84,840 on Bitstamp.

Better-than-expected US corporate earnings had helped spark a rally across both crypto and stock markets in recent sessions. Tesla's results, released after the Wall Street closing bell, did not deliver the same promising signals as those from SpaceX and General Motors earlier in the week.

The company reported Q3 revenue of $28.05 billion, just short of Bloomberg's $28.13 billion estimate. Capital expenditure, however, came in at $4.73 billion, well below the projected $7.96 billion. The underspend appeared to fuel concerns over the AI sector as markets continued to recover from last week's Asia tech-stock sell-off. Capex has become a key gauge of how aggressively major technology firms are committing to AI infrastructure, making the underspend the figure that drew the market's attention.

"Lower capex suggests less of an 'all-in' approach to the AI arms race than one would expect from Elon," Ryan Lee, senior vice president of product and strategy at Direxion, told Reuters, referring to Tesla CEO Elon Musk.

Speaking on the company's earnings call, Musk said spending would rise through 2028.

"I think capex is actually ending up being a little lower than we anticipated, but we'll start to become more meaningful next year. And then noticeable in the tens of billions in '28," he said, as quoted by Bloomberg.

South Korea's tech-heavy KOSPI Composite Index — the country's benchmark stock gauge and a commonly cited barometer of sentiment toward the technology sector — finished Thursday's session down 3.52%, struggling to sustain a recovery after dropping to 5,460 points last week, its lowest level since late July.

Lower high persists as trend line resistance holds

Onchain data showed a marked increase in open interest (OI) — the total value of outstanding derivative positions — across crypto trading platforms in the run-up to Bitcoin's reversal.

Related: XRP 30-day exchange inflows pass 6B tokens as whales move to the sidelines

OI reached $55.95 billion late Tuesday, according to CoinGlass figures, after gaining 4.5% over 24 hours to reach its highest tally since Sept. 25. Increases of this kind heighten the market's susceptibility to long or short cascades that can turn brief reversals into deeper corrections — cascades that unfold when leveraged positions moving against their holders are forcibly liquidated, with each wave of liquidation able to push price further and set off the next.

On three-day time frames, BTC/USD was rejected at a downward-sloping trend line, preserving a cycle of lower highs — a structure in which each rally attempt tops out below the previous peak and is typically read as fading upside momentum until resistance gives way. On Tuesday, crypto trader and analyst Rekt Capital argued that this trend line resistance needed to be broken as a prerequisite for sustained upside momentum.

As previously reported by Cointelegraph, the area between $80,000 and $81,500 is now forming key support because it hosts the cost basis — the average price at which accumulated coins were purchased — for US spot Bitcoin exchange-traded funds (ETFs), a level watched because it marks where those holders sit at break-even. With the downward-sloping trend line overhead and the ETF cost-basis zone beneath, BTC sits between the two reference levels currently defining its range: a break above the former is what Rekt Capital views as the prerequisite for renewed upside, while the latter is the support zone highlighted in prior Cointelegraph reporting.

This article was first published by Cointelegraph.