Calls are for when you think price goes up. Puts are for when you think price goes down or want to protect your holdings. But knowing which to buy and when goes deeper than just bullish or bearish.

In this guide, you'll learn when to use calls, when to use puts, how to choose strike prices, and how to match time periods to your trading thesis. By the end, you'll know exactly which option to buy for any market scenario.

A call option gives you the right to buy an asset at a fixed price (strike price) before expiration. You buy calls when you think price will go up. It's that simple. But the details matter.

You should buy calls when you have a bullish thesis. Maybe ETH is consolidating and you expect a breakout. Maybe there's a major upgrade coming that could pump price. Maybe you see a pattern forming that signals upside. Whatever the reason, you think price is going higher.

Calls give you leveraged exposure to that upside. Instead of buying 10 ETH for $30,000, you can buy 10 call options for $1,500 and control the same exposure. If you're right and ETH pumps, your percentage returns are massive. If you're wrong, you lose the $1,500 premium, not $30,000.

Not all calls are created equal. Your strike price determines how far price needs to move for you to profit.

ATM (At-The-Money) calls have a strike at the current price. If ETH is $3,000, an ATM call has a $3,000 strike. These are the most expensive but easiest to profit from. Any move above $3,000 puts you in profit (after premium).

OTM +10% calls have a strike 10% above current price. If ETH is $3,000, the strike is $3,300. These are cheaper than ATM but require a bigger move to profit. They're the sweet spot for most traders, balanced risk and reward.

OTM +20% calls have a strike 20% above current price. Even cheaper premium, but ETH needs to pump hard for you to profit. Good for high-conviction plays where you expect a major move.

OTM +30% calls are the lottery tickets. Strike is 30% above current price. Very cheap premium, but extremely unlikely to profit unless something wild happens. Only buy these if you're willing to lose the entire premium.

Time is working against you with calls. The longer until expiration, the more premium you pay, but you give yourself more time to be right.

7-day calls are for quick plays. You have high conviction that ETH will pump this week. Maybe there's a catalyst or breakout imminent.

14-30 day calls are standard. You think ETH will pump over the next few weeks. This gives you breathing room for your thesis to play out without paying massive premium for long duration.

90-day calls are for long-term bullish theses. You're confident ETH is going higher but don't know exactly when. You pay more premium but get months for the move to happen.

Let's say ETH is at $3,000. You see consolidation forming and expect a breakout to $3,450 within the next week. You're not certain, but you're confident.

You buy 10 call options:

• Strike: $3,000 (ATM)

• Period: 7 days

• Premium: Let's say $150 per call

• Total cost: $1,500

One week later, ETH pumps to $3,450 like you expected. You exercise your calls:

• Profit: ($3,450 - $3,000) × 10 = $4,500

• Minus premium: -$1,500

• Net profit: $3,000

• ROI: 200%

If you had bought 0.5 ETH instead with your $1,500, you'd have made $225 (15% gain). With calls, you made $3,000. That's 13x more profit.

But if ETH stayed flat or dropped, you'd lose the entire $1,500 premium. Calls amplify gains and limit losses to premium paid.

A put option gives you the right to sell an asset at a fixed price (strike price) before expiration. You buy puts when you think price will go down, or when you want to protect holdings from a drop.

Puts serve two purposes: speculation and protection.

For speculation: You think ETH is going to dump. Maybe the chart looks weak. Maybe macro conditions are bearish. Maybe there's FUD brewing. You buy puts to profit from the decline without shorting (which has unlimited risk).

For protection: You hold ETH and want insurance. You're long-term bullish but worried about short-term volatility. Or you have an LP position and want to hedge against impermanent loss. Puts act as insurance, you pay a premium for downside protection.

Just like calls, strike selection determines your protection level or profit threshold.

ATM (At-The-Money) puts have a strike at the current price. If ETH is $3,000, an ATM put has a $3,000 strike. These provide maximum protection. Any move below $3,000 is covered (after premium).

OTM -10% puts have a strike 10% below current price. If ETH is $3,000, the strike is $2,700. These are cheaper than ATM but only protect below $2,700. This is the most common hedge, you accept the first 10% of downside and protect everything beyond that.

OTM -20% puts have a strike 20% below current price. Even cheaper, but only protect below $2,400 (if ETH is $3,000). Good for cost-effective protection against larger drops.

OTM -30% puts are black swan insurance. Strike is 30% below current price. Very cheap premium, but only pays out in extreme crashes. Good for protecting against worst-case scenarios.

Same principle as calls, longer duration costs more but gives you more time.

7-day puts are for short-term events. Maybe there's uncertainty this week. Maybe earnings or announcements coming. You want protection just for the next few days.

14-30 day puts are standard hedging periods. You want protection for the next month while you hold your position or wait out volatility.

90-day puts are long-term insurance. You're holding ETH for months but want downside protection in case things go south.

You hold 10 ETH currently worth $30,000 (ETH at $3,000). You're long-term bullish but worried about short-term volatility. Maybe there's a Fed announcement coming. Maybe the chart looks weak. You want protection.

You buy 10 put options:

• Strike: $2,700 (OTM -10%)

• Period: 30 days

• Premium: Let's say $80 per put

• Total cost: $800

If ETH dumps to $2,400 within 30 days:

• Your ETH value: $24,000 (loss of $6,000)

• Put profit: ($2,700 - $2,400) × 10 = $3,000

• Minus premium: -$800

• Net put profit: $2,200

• Total position: $24,000 + $2,200 = $26,200

Instead of losing $6,000, you only lost $3,800. The put absorbed $2,200 of the downside. You paid $800 for $2,200 of protection, a 2.7x return on your insurance.

If ETH stayed above $2,700, your puts expire and you lose the $800 premium. But your ETH is still worth $30,000+ and you held through volatility with peace of mind.

That's insurance.

Here's how to decide:

Bullish? → Buy calls

Bearish? → Buy puts

Neutral but holding assets? → Buy puts for protection

Want leverage? → Calls give you upside exposure with limited capital

Want protection? → Puts hedge your holdings

Want to profit from a dump? → Puts let you short without unlimited risk

Very confident? → ATM (more expensive but easier to profit)

Moderately confident? → OTM +/-10% (balanced)

High conviction, big move expected? → OTM +/-20%

Moon shot or black swan? → OTM +/-30%

Quick trade (this week)? → 7 days

Standard swing trade? → 14-30 days

Long-term thesis? → 90 days

New traders see cheap premiums on OTM +30% calls and think "This is a steal!" But there's a reason they're cheap, price rarely moves 30% before expiration. You're buying lottery tickets.

Fix: Stick to ATM or OTM +10% until you understand how options move.

You buy 7-day calls because premium is cheap. But your thesis takes 2 weeks to play out. The option expires even though you were eventually right.

Fix: Match duration to your thesis. If you think ETH pumps "soon," buy 14-30 days to give yourself room.

You hold 10 ETH and buy 20 puts "just to be safe." Now you're paying double premium for protection you don't need. If ETH stays flat, you lose massive premium.

Fix: Hedge 50-75% of your position, not 100-200%. Leave some upside unhedged.

Your call is deep ITM with days left until expiration. You think "I'll wait for max profit." Price reverses and your profit disappears.

Fix: Take profit when you have it. Exercise ITM options or sell them. Don't be greedy.

You have a $30,000 LP position in ETH/USDm. ETH is at $3,000. You're earning fees but worried about impermanent loss if ETH moves 20%+ in either direction.

You buy 10 put options:

• Strike: $2,700 (OTM -10%)

• Period: 30 days

• Premium: $80 per put = $800 total

If ETH dumps to $2,400:

• Your LP position suffers IL of ~$1,800

• Your put profit: ($2,700 - $2,400) × 10 = $3,000

• Minus premium: -$800

• Net put profit: $2,200

• IL offset: $2,200 - $1,800 = $400 net gain

Your LP position is protected. The put gains offset the IL and you even profit slightly. Plus you kept earning fees the whole time. This is how you hedge LP positions effectively.

Calls = Bullish plays or leverage

Puts = Bearish plays or protection

Strike selection = How confident you are

Time period = How long your thesis takes

Start with ATM or OTM +/-10%. Give yourself enough time (14-30 days minimum). Don't over-hedge. Take profit when you have it.

Options are powerful tools when used correctly. Now you know when to use each.

MegaFi brings calls and puts to MegaETH with advantages impossible on other chains:

Traditional platforms update prices every 15+ seconds. By the time you see a quote, it's stale. MegaFi updates continuously in real-time. You see accurate pricing the moment you check. No stale quotes. No slippage surprises.

Submit your trade and it executes in under 10 milliseconds. Traditional platforms take 15-30 seconds. In volatile markets, that delay costs you money. On Hedge, you get your price.

All premiums calculated on-chain using Black-Scholes. No hidden fees. No market maker markup. What you see is what you pay.

Your calls and puts are ERC721 NFTs. Transfer them. Sell them. Use them in other protocols. True ownership. True composability.

Gas fees under $0.005 per transaction. Execute multiple options trades for less than a dollar in gas. On MegaETH, trading options is actually affordable.

This is options trading at MegaETH speed with MegaFi.

Real-time pricing. Instant execution. Transparent settlement.

This article is for educational purposes only and does not constitute financial advice. Options trading involves substantial risk. You can lose your entire premium. All examples are hypothetical and speculative. Actual results will vary based on market conditions, timing, and execution. Options are complex instruments, only trade if you understand the risks. Always do your own research and consider your risk tolerance.