Friendly reminder:
Please do not invest money you can't afford to lose.

A thread about GameStop:

Big hedge funds made big bets that GameStop’s stock was overvalued. The way these bets work is the hedge fund borrows shares of the stock and sells those borrowed shares.

When it comes time to give the borrowed shares back, they buy them on the market, hopefully at lower prices. For example, they might sell the borrowed share at $50, hoping to be able to buy the share back at $30, to make a $20 profit. This is called shorting.

The hedge funds were so sure that GameStop was going down, that GameStop was the most shorted stock on the market. 140% of the shares in existence were “borrowed.” Imagine Bob borrows from Jane who borrows from Sue who borrows from John.

Shorting is risky, but the hedge funds were so sure that they just didn’t even care. People on Reddit realized this and basically thought “what if we all just bought shares and refused to sell them when the hedge funds need to give their borrowed shares back.”

The price goes up, the hedge funds are forced to buy back the expensive shares and lose money. Except the hedge funds kept doubling down as the price rode up, expecting that it would eventually fall. The Redditors weren't scared off and with "diamond hands" refused to sell.

1/x Vanna is back & ready to turn back on the charm! Overnight the market hit our weeklong target of **3705 and pulled back... We were able to take profits & play for a bit of morning digestion. It’s been a nice +3.5% in a week w/a few extra scalps along the way...But the best

2/x part has been the gift of Vol compression, which along w/ short Vol profits, has given us significant calendar expansion & dispersion opps, as predicted. I expect this to continue this week as well, as Ivol oversupply should continue to be the dominant force until 12/11.This,

3/x paired w/ the significantly increasing Vanna & Charm flows, will make it hard for any decline until 12/14 to catch meaningful momentum. This said, the narrowing of 20 day RVol as well as the 2 stddev of the 20 day just overhead should cap any rallies, given the dramatically

4/x overextended retail (8-day SMA of P/C equity is the lowest in 20 years) & institutional positioning. This push/pull, should ultimately keep the market fairly pinned this week...Jan 8th call’s on back are incredibly cheap w/ a GA runoff event straddle of only $55, which given

5/x the potential macro-cyclical consequences of the next 2 years of fiscal stimulus seems absurd...& In terms of a more short term trade,Tesla Vol is either too high or 12/18 on back calendar spreads in the SPX are too low, as there’s no premium being priced in for the inclusion

Working on some execution optimisation related backtesting. I have so far been executing with market orders only. Going towards higher lot sizes, I'd like to optimise for minimal slippage.

First off, on NSE, if you place a market order, you get filled at the best bid/ask right?

If we want to optimise this, the first non-creative idea one can think of is, slicing the order into different lot sizes, and placing a limit order for each slice at the mid point of current best bid & ask.

But this requires your latency to be the least.

Why would latency affect it?

I looked at tick historical data, and there are more than 18-20 ticks in a second (auction and quote combined).

Even if you keep 10 ticks per second, your best bid/ask can shift from the time you place to the time exchange receives the order.

So, the next best thing that people can do is place tranches of orders every 1s, 3s, 5s, 10s, 15s - in their preferred time range, and get filled at the midpoint or best-bid+1/2/3/4/5 in the depth.

What you need is liquidity.

But if you're trading breakouts, then it's highly likely that your limit orders may not get filled if the action is too fast.

So, a retry mechanism is required in such cases.

If nothing works, you convert your orders to marketable and get filled at worse slippage.